|
Digital Camera Patent Abstract
An digital camera device is disclosed having a digital zoom function
in order to form an output image, which device includes a sensor
and optics to produce an primary image, a display in which the primary
image is arranged to be cropped in connection with the digital zoom
function in order to form the said output image, user interface
means to set one or more settings relating to the digital zoom function
and a image processor which is arranged to put a size for the said
output image based on the cropping of the primary image at least
in part of an digital zoom range. In the user interface is arranged
to be set as the said setting one or more size limit for the said
output image and based on the one or more size limit and the size
of the cropped primary image, the image processor is arranged to
perform scaling operations for the cropped primary image at least
in part of the digital zoom range defined by the said one or more
size limit. In addition the invention also relates to corresponding
methods and program products.
Digital Camera Patent Claims
1. Digital camera device having a digital zoom function in order
to form an output image, which device includes a sensor and optics
to produce an primary image, a display in which the primary image
is arranged to be cropped in connection with the digital zoom function
in order to form the said output image, user interface means to
set one or more settings relating to the digital zoom function and
image processor which is arranged to put a size for the said output
image based on the cropping of the primary image at least in part
of an digital zoom range, characterized in that in the user interface
is arranged to be set as the said setting one or more size limit
for the said output image and based on the one or more size limit
and the size of the cropped primary image, the image processor is
arranged to perform scaling operations for the cropped primary image
at least in part of the digital zoom range defined by the said one
or more size limit.
2. Digital camera device according to claim 1, characterized in
that the size limit is a minimum size for the said output image
to which size the image processor is arranged to upscale the cropped
primary image if the size of that is below the said minimum size.
3. Digital camera device according to claim 1, characterized in
that the size limit is a maximum size for the said output image
to which size the image processor is arranged to downscale the cropped
primary image if the size of that exceeds the said maximum size.
4. Digital camera device according to claim 2, characterized in
that the size limit includes in addition a maximum size for the
said output image to which size the image processor is arranged
to downscale the cropped primary image if the size of that exceeds
the said maximum size.
5. Digital camera device according to claim 4, characterized in
that the size limit includes in addition at least one output image
size for the said output image to which size the image processor
is arranged to scale the cropped primary image in an established
manner if the size of that is between the said minimum size and
the said maximum size.
6. Digital camera device according to claim 5, characterized in
that the digital zoom range between the set minimum size limit and
the set maximum size limit is arranged to be quantized by the set
output image size limits on the basis of which is arranged to be
set the size for the cropped primary image in an established manner.
7. Digital camera device according to claim 1, characterized in
that a data of the primary image is arranged to be used to determine
imaging setups.
8. Digital camera device having a digital zoom function in order
to form an output image, which device includes a sensor and optics
in order to produce an primary image, a display in which the primary
image is arranged to be cropped in connection with the digital zoom
function in order to form the said output image and image processor
which is arranged to store the output image using a quality factor
set for it, characterized in that the quality factor is connected
to the size of the cropped primary image.
9. Digital camera device according to claim 8, characterized in
that the quality factor is calculated by using the equation of:qf_new=qf_old+({1.0-scale}*{max[96,
qf_old]-qf_old})whereinscale=(crop.sub.--xsize/original.sub.--xsize)*(cro-
p.sub.--ysize/original.sub.--ysize)and in which qf_new=new quality
factor, qf_old=old quality factor, crop_xsize=size of ROI in vertical
direction crop_ysize=size of ROI in horizontal direction and original_xsize,
original_ysize=size of primary image produced by sensor.
10. Digital camera device having a digital zoom function in order
to form an output image, which device includes a sensor and optics
to produce an primary image, a display in which the primary image
is arranged to be cropped in connection with the digital zoom function
in order to form the said output image, user interface means to
set one or more settings relating to the digital zoom function and
image processor which is arranged to put a size for the said output
image based on the cropping of the primary image and to store the
said output image using a quality factor set for it, characterized
in that in the user interface is arranged to be set as the said
setting one or more size limit for the said output image and based
on the one or more size limit and the size of the cropped primary
image, the image processor is arranged to perform scaling operations
for the cropped primary image at least in part of the digital zoom
range defined by the said one or more size limit and the said quality
factor is connected to the size of the cropped primary image.
11. Digital camera device having a digital zoom function in order
to form an output image, which device includes a sensor and optics
to produce an primary image, a display in which the primary image
is arranged to be viewed in connection with a digital imaging, user
interface means to set one or more settings relating to the digital
zoom function and image processor which is arranged to process the
primary image in order to form the said output image, characterized
in that in the user interface is arranged to be set as the said
setting at least one size setting for the said output image and
the image processor is arranged to perform scaling operations for
the primary image as the said processing in order to produce the
output image having the size of the set size setting.
12. Digital camera device according to claim 11, characterized
in that the size setting is a minimum size for the said output image
to which size the image processor is arranged to upscale the primary
image if the size of that is below the said minimum size.
13. Method in digital zooming procedure in order to form an output
image in which method user sets one or more settings relating to
the digital zooming procedure, an primary image is produced, the
primary image is cropped in connection with the digital zooming
procedure in order to form the said output image, a size for the
said output image is put on the basis of the cropping of the primary
image at least in part of an digital zoom range, characterized in
that for the said output image is set as the said setting one or
more size limit and based on the one or more size limit and the
size of the cropped primary image is performed scaling operations
for the cropped primary image at least in part of the digital zoom
range defined by the said one or more size limit.
14. Method according to claim 13, characterized in that the size
limit is a minimum size for the said output image to which size
the cropped primary image is upscaled if the size of that is below
the said minimum size.
15. Method according to claim 13, characterized in that the size
limit is a maximum size for the said output image to which size
the cropped primary image is downscaled if the size of that exceeds
the said maximum size.
16. Method according to claim 14, characterized in that the size
limit includes in addition a maximum size for the said output image
to which size the cropped primary image is downscaled if the size
of that exceeds the said maximum size.
17. Method according to claim 16, characterized in that the size
limit includes in addition at least one output image size for the
said output image to which size the cropped primary image is scaled
in an established manner if the size of that is between the said
minimum size and the said maximum size.
18. Method according to claim 17, characterized in that the digital
zoom range between the set minimum size limit and the set maximum
size limit is quantized by the set output image size limits on the
basis of which is set the size for the cropped primary image in
an established manner.
19. Method according to claim 13, characterized in that a data
of the primary image is used to determine imaging setups.
20. Method in digital zooming procedure in order to form an output
image in which method an primary image is produced, the primary
image is cropped in connection with the digital zooming procedure
in order to form the said output image and the output image is stored
using a quality factor set for it, characterized in that the quality
factor is calculated on the basis of the size of the cropped primary
image.
21. Method according to claim 20, characterized in that the quality
factor is calculated by using the equation of:qf_new=qf_old+({1.0-scale}*{max[96,
qf_old]-qf_old})whereinscale=(crop.sub.--xsize/original.sub.--xsize)*(cro-
p.sub.--ysize/original.sub.--ysize)and in which qf_new=new quality
factor, qf_old=old quality factor, crop_xsize=size of ROI in vertical
direction crop_ysize=size of ROI in horizontal direction and original_xsize,
original_ysize=size of primary image produced by sensor.
22. Method in digital zooming procedure in order to form an output
image in which method user sets one or more settings relating to
the digital zooming procedure, an primary image is produced, the
primary image is cropped in connection with the digital zooming
procedure in order to form the said output image, a size for the
said output image is put on the basis of the cropping of the primary
image and the output image is stored using a quality factor set
for it, characterized in that for the said output image is set as
the said setting one or more size limit and based on the one or
more size limit and the size of the cropped primary image is performed
scaling operations for the cropped primary image at least in part
of the digital zoom range defined by the said one or more size limit
and the said quality factor is calculated on the basis of the size
of the cropped primary image.
23. Method in digital zooming procedure in order to form an output
image in which method user sets one or more settings relating to
the digital zooming procedure, an primary image is produced and
the primary image is processed in order to form the said output
image, characterized in that for the said output image is set as
the said setting at least one size setting and for the primary image
is performed scaling operations as the said processing in order
to produce the output image having the size of the set size setting.
24. Method according to claim 23, characterized in that the size
setting is a minimum size for the said output image to which size
the primary image is upscaled if the size of that is below the said
minimum size.
25. Program product for performing digital zoom function in order
to form an output image in a digital camera device, which program
product include a storing means and a program code executable by
a processor and written in the storing means, which program code
includes first code means configured to set one or more settings
via a user interface relating to the digital zoom function, second
code means configured in connection with the digital zoom function
to crop in the user interface a primary image produced by an imaging
means in order to form the said output image and third code means
configured to put a size for the said output image on the basis
of the cropping of the primary image at least in part of an digital
zoom range, characterized in that the program code includes fourth
code means configured in the user interface to set as the said setting
one or more size limit for the said output image and fifth code
means configured to perform scaling operations for the cropped primary
image at least in part of the digital zoom range defined by the
said one or more size limit which scaling operations is arranged
to be based on the one or more size limit and the size of the cropped
primary image.
26. Program product according to claim 25, characterized in that
the size limit is a minimum size for the said output image and the
program code comprises sixth code means configured to upscale the
cropped primary image to the said minimum size if the size of the
cropped image is below the said minimum size.
27. Program product according to claim 25, characterized in that
the size limit is a maximum size for the said output image and the
program code comprises seventh code means configured to downscale
the cropped primary image to the said maximum size if the size of
the cropped image exceeds the said maximum size.
28. Program product according to claim 26, characterized in that
the size limit includes in addition a maximum size for the said
output image and the program code includes eighth code means configured
to downscale the cropped primary image to the said maximum size
if the size of the cropped image exceeds the said maximum size.
29. Program product according to claim 28, characterized in that
the size limit includes in addition at least one output image size
for the said output image and the program code includes ninth code
means configured to scale the cropped primary image to the said
output image size in an established manner if the size of the cropped
primary image is between the said minimum size and the said maximum
size.
30. Program product according to claim 29, characterized in that
the program code includes ninth code means configured to quantize
by the set output image size limits the digital zoom range between
the set minimum size limit and the set maximum size limit and on
the basis of quantization to set the size for the cropped primary
image in an established manner.
31. Program product according to claim 25, characterized in that
the program code includes tenth code means configured to determine
imaging setups using a data of the primary image.
32. Program product for performing digital zoom function in order
to form an output image in a digital camera device, which program
product include a storing means and a program code executable by
a processor and written in the storing means, which program code
includes first code means configured in connection with the digital
zoom function to crop in the user interface a primary image produced
by an imaging means in order to form the said output image and second
code means configured to store the output image using a quality
factor set for it, characterized in that the program code includes
third code means configured to determine the quality factor to be
used based on the size of the cropped primary image.
33. Program product according to claim 32, characterized in that
the program code includes fourth code means configured to calculate
the quality factor by using the equation of:qf_new=qf_old+({1.0-scale}*{max[96,
qf_old]-qf_old})whereinscale=(crop.sub.--xsize/original.sub.--xsize)*(cro-
p.sub.--ysize/original.sub.--ysize)and in which qf_new=new quality
factor, qf_old=old quality factor, crop_xsize=size of ROI in vertical
direction crop_ysize=size of ROI in horizontal direction and original_xsize,
original_ysize=size of primary image produced by sensor.
34. Program product for performing digital zoom function in order
to form an output image in a digital camera device, which program
product include a storing means and a program code executable by
a processor and written in the storing means, which program code
includes first code means configured to set one or more settings
via a user interface relating to the digital zoom function, second
code means configured in connection with the digital zoom function
to crop in the user interface a primary image produced by an imaging
means in order to form the said output image, third code means configured
to put a size for the said output image on the basis of the cropping
of the primary image at least in part of an digital zoom range and
code means configured to store the output image using a quality
factor set for it, characterized in that the program code includes
fourth code means configured in the user interface to set as the
said setting one or more size limit for the said output image, fifth
code means configured to perform scaling operations for the cropped
primary image at least in part of the digital zoom range defined
by the said one or more size limit which scaling operations is arranged
to be based on the one or more size limit and the size of the cropped
primary image and code means configured to determine the quality
factor to be used based on the size of the cropped primary image.
35. Program product for performing digital zoom function in order
to form an output image in a digital camera device, which program
product include a storing means and a program code executable by
a processor and written in the storing means, which program code
includes first code means configured to set one or more settings
via a user interface relating to the digital zoom function, second
code means configured in connection with the digital zoom function
to view in the user interface a primary image produced by an imaging
means in order to form the said output image and third code means
configured to process the primary image in order to form the said
output image, characterized in that the program code includes fourth
code means configured in the user interface to set as the said setting
at least one size setting for the said output image and fifth code
means configured to perform scaling operations for the primary image
as the said processing in order to produce the output image having
the size of the set size setting.
36. Program product according to claim 35, characterized in that
the size setting is a minimum size for the said output image and
the program code comprises sixth code means configured to upscale
the primary image to the said minimum size if the size of the image
is below the said minimum size.
Digital Camera Patent Description
FIELD OF THE INVENTION
[0001] The invention concerns digital camera device having a digital
zoom function in order to form an output image, which device includes
[0002] a sensor and optics to produce an primary image, [0003] a
display in which the primary image is arranged to be cropped in
connection with the digital zoom function in order to form the said
output image, [0004] user interface means to set one or more settings
relating to the digital zoom function and [0005] a image processor
which is arranged to put a size for the said output image based
on the cropping of the primary image at least in part of an digital
zoom range.
[0006] In addition, the invention also concerns methods and corresponding
program products.
BACKGROUND OF THE INVENTION
[0007] Zoom is used in digital cameras to crop out uninteresting
parts of the view and to enlarge the interesting part of the view.
Optical zoom genuinely enlarges the image and introduces new details
and information to the image.
[0008] Digital zoom is also commonly included in digital cameras,
either as a method to complement the optical zoom or as the sole
zooming method in low-end digital cameras. Digital zoom uses the
primary image that is produced by the camera optics and imaging
sensor as the input, and thus digital zoom does not introduce genuine
new details to the image. Digital zoom either crops the input image
and thus reduces the image resolution, or crops the input image
and then interpolates, or in more general, upscales the image to
some higher resolution than the cropped resolution, for example,
back to the original input resolution.
[0009] No information is lost from the ROI (Region of Interest)
in the cropping but only the information outside ROI. Similarly,
no genuine new information is introduced in the interpolation; new
values are estimated into each location (x, y) of the output image
according to certain neighbourhood of pixels that correspond to
location (x, y) in the cropped input image. For example, bilinear
or bicubic interpolation are typically used in connection with this
measure.
[0010] Typically the digital zoom in digital cameras operates fairly
like next. The input primary image produced by sensor and optics
is cropped according to the digital zoom factor and then the cropped
image is interpolated back to the original resolution in order to
produce the final output image. The activation of digital zoom in
UI (User Interface) varies a lot.
[0011] Some manufacturers have a bit more sophisticated digital
zoom methods. For example, Sony has "SmartZoom" concept
that is introduced in some devices [1]. It operates like fairly
like this: 1) user selects output_resolution. This must be lower
than the original_sensor_resolution. 2) user enables SmartZoom.
3) the user uses zoom ring to zoom (i.e. optical zoom). 4) the system
crops output_resolution_sized subimage from the original image.
The resolution of that is original_sensor_resolution.
[0012] Thus, when using SmartZoom, the minimum zoom factor i.e.
optical+digital is not x1, but it is (original_sensor_resolution/output_resolution).
This is bigger than x1. The maximum zoom factor is increased to
{optical_zoom_factor*(original_sensor_resolution/output_resolution)}.
[0013] SmartZoom does not deteriorate the image quality as much
as the traditional digital zoom methods, which is due to use of
simple cropping instead of interpolation+downscaling combination.
However, user cannot enable SmartZoom before he selects lower resolution
than original_sensor_resolution as the output_resolution.
[0014] Also, HP PhotoSmart 935 digital camera [2] has at least
following digital zoom features 1) no interpolation is used, only
cropping and 2) the actual pixel size that results from the digital
zoom (cropping) is displayed on the viewfinder. According to quick
tests, the JPEG compression factor seems to change from a fixed
setting A into fixed setting B when digital zoom is performed.
[0015] The prior art solutions above doesn't take into account
different kind of further use applications. One of these is to produce
a hard copy. Image quality problems arise due to the consecutive
scaling measures that are performed in both directions (i.e. upscaling
and downscaling). Problems arise also due to the fact that scaling
measures are performed as postprocessing. This causes to the image,
for example, artefacts.
SUMMARY OF THE INVENTION
[0016] The purpose of the present invention is to bring about ways
to perform digital zooming procedure with digital camera devices.
The invention is a digital zoom system (UI and system level inventions)
for devices that contain digital camera sensor(s). The characteristic
features of the digital camera devices according to the invention
are presented in the appended claims 1, 8, 10 and 11 and the characteristic
features of the methods are presented in claims 13, 20, 22 and 23.
In addition, the invention also concerns program products, whose
characteristic features are presented in the appended claims 25,
32, 34 and 35.
[0017] In the invention, when the end user performs digital imaging,
the invention instructs the processor of the device how to perform
a smart digital zoom function that there is always a benefit in
connection with the further use or processing of the produced digital
image. The digital zooming has now performed in dynamical manner.
The user may set one or more size limits or size setting for the
output image size based on which the suitable scaling measures are
then performed.
[0018] The first digital camera device according to the invention
has a digital zoom function in order to form an output image. The
device includes a sensor and optics to produce an primary image,
a display in which the primary image is arranged to be cropped in
connection with the digital zoom function in order to form the said
output image, user interface means to set one or more settings relating
to the digital zoom function and image processor which is arranged
to put a size for the said output image based on the cropping of
the primary image at least in part of an digital zoom range. In
the user interface of the device is arranged to be set as the said
setting one or more size limit for the said output image and based
on the one or more size limit and the size of the cropped primary
image, the image processor is arranged to perform scaling operations
for the cropped primary image at least in part of the digital zoom
range defined by the said one or more size limit.
[0019] The second digital camera device according to the invention
includes also a sensor and optics in order to produce an primary
image, a display in which the primary image is arranged to be cropped
in connection with the digital zoom function in order to form the
said output image and image processor which is arranged to store
the output image using a quality factor set for it. The quality
factor is connected to the size of the cropped primary image.
[0020] The third digital camera device according to the invention
includes also a digital zoom function in order to form an output
image. The device includes a sensor and optics to produce an primary
image, a display in which the primary image is arranged to be cropped
in connection with the digital zoom function in order to form the
said output image, user interface means to set one or more settings
relating to the digital zoom function and image processor which
is arranged to put a size for the said output image based on the
cropping of the primary image and to store the said output image
using a quality factor set for it. In the user interface is arranged
to be set as the said setting one or more size limit for the said
output image and based on the one or more size limit and the size
of the cropped primary image, the image processor is arranged to
perform scaling operations for the cropped primary image at least
in part of the digital zoom range defined by the said one or more
size limit and the said quality factor is connected to the size
of the cropped primary image.
[0021] The fourth digital camera device according to the invention
includes a digital zoom function in order to form an output image.
In addition the device includes a sensor and optics to produce an
primary image, a display in which the primary image is arranged
to be viewed in connection with a digital imaging, user interface
means to set one or more settings relating to the digital zoom function
and image processor which is arranged to process the primary image
in order to form the said output image. In the user interface is
arranged to be set as the said setting at least one size setting
for the said output image and the image processor is arranged to
perform scaling operations for the primary image as the said processing
in order to produce the output image having the size of the set
size setting.
[0022] Furthermore, the invention concerns also first method to
be performed in connection with a digital zoom function in order
to form an output image. In the method user sets one or more settings
relating to the digital zooming procedure, an primary image is produced,
the primary image is cropped in connection with the digital zooming
procedure in order to form the said output image, a size for the
said output image is put on the basis of the cropping of the primary
image at least in part of an digital zoom range. For the said output
image is set as the said setting one or more size limit and based
on the one or more size limit and the size of the cropped primary
image is performed scaling operations for the cropped primary image
at least in part of the digital zoom range defined by the said one
or more size limit.
[0023] The invention concerns also second method to be performed
in connection with a digital zooming procedure in order to form
an output image in which method an primary image is produced, the
primary image is cropped in connection with the digital zooming
procedure in order to form the said output image and the output
image is stored using a quality factor set for it. The quality factor
is calculated on the basis of the size of the cropped primary image.
[0024] The invention concerns also third method to be performed
in connection with digital zooming procedure in order to form an
output image in which method user sets one or more settings relating
to the digital zooming procedure, an primary image is produced,
the primary image is cropped in connection with the digital zooming
procedure in order to form the said output image, a size for the
said output image is put on the basis of the cropping of the primary
image at least in part of an digital zoom range and the output image
is stored using a quality factor set for it. For the said output
image is set as the said setting one or more size limit and based
on the one or more size limit and the size of the cropped primary
image is performed scaling operations for the cropped primary image
at least in part of the digital zoom range defined by the said one
or more size limit and the said quality factor is calculated on
the basis of the size of the cropped primary image.
[0025] The invention concerns also fourth method to be performed
in connection with digital zooming procedure in order to form an
output image in which method user sets one or more settings relating
to the digital zooming procedure, an primary image is produced and
the primary image is processed in order to form the said output
image. For the said output image is set as the said setting at least
one size setting and for the primary image is performed scaling
operations as the said processing in order to produce the output
image having the size of the set size setting.
[0026] Furthermore, the first program product for performing digital
zoom function in order to form an output image in a digital camera
device includes a storing means and a program code executable by
a processor and written in the storing means. The program code includes
first code means configured to set one or more settings via a user
interface relating to the digital zoom function, second code means
configured in connection with the digital zoom function to crop
in the user interface a primary image produced by an imaging means
in order to form the said output image and third code means configured
to put a size for the said output image on the basis of the cropping
of the primary image at least in part of an digital zoom range.
In addition, the program code also includes fourth code means configured
in the user interface to set as the said setting one or more size
limit for the said output image and fifth code means configured
to perform scaling operations for the cropped primary image at least
in part of the digital zoom range defined by the said one or more
size limit which scaling operations is arranged to be based on the
one or more size limit and the size of the cropped primary image.
[0027] The second program product for performing digital zoom function
in order to form an output image in a digital camera device includes
a storing means and a program code executable by a processor and
written in the storing means, and which program code includes first
code means configured in connection with the digital zoom function
to crop in the user interface a primary image produced by an imaging
means in order to form the said output image and second code means
configured to store the output image using a quality factor set
for it. In addition, the program code also includes third code means
configured to determine the quality factor to be used based on the
size of the cropped primary image.
[0028] The third program product for performing digital zoom function
in order to form an output image in a digital camera device, which
program product include a storing means and a program code executable
by a processor and written in the storing means, which program code
includes first code means configured to set one or more settings
via a user interface relating to the digital zoom function, second
code means configured in connection with the digital zoom function
to crop in the user interface a primary image produced by an imaging
means in order to form the said output image, third code means configured
to put a size for the said output image on the basis of the cropping
of the primary image at least in part of an digital zoom range and
code means configured to store the output image using a quality
factor set for it. The program code also includes fourth code means
configured in the user interface to set as the said setting one
or more size limit for the said output image, fifth code means configured
to perform scaling operations for the cropped primary image at least
in part of the digital zoom range defined by the said one or more
size limit which scaling operations is arranged to be based on the
one or more size limit and the size of the cropped primary image
and code means configured to determine the quality factor to be
used based on the size of the cropped primary image.
[0029] The fourth program product for performing digital zoom function
in order to form an output image in a digital camera device, which
program product include a storing means and a program code executable
by a processor and written in the storing means, which program code
includes first code means configured to set one or more settings
via a user interface relating to the digital zoom function, second
code means configured in connection with the digital zoom function
to view in the user interface a primary image produced by an imaging
means in order to form the said output image and third code means
configured to process the primary image in order to form the said
output image. The program code also includes fourth code means configured
in the user interface to set as the said setting at least one size
setting for the said output image and fifth code means configured
to perform scaling operations for the primary image as the said
processing in order to produce the output image having the size
of the set size setting.
[0030] The size limit or sizes according to the invention may be,
for example, a minimum size for the said output image, a maximum
size for the said output image or at least one output size for an
output image. Other limits are also possible. Different kinds of
combinations of the listed limits above are also possible. The scaling
operations may be upscaling and/or downscaling. The size limits
defines which scaling operations has been performed, if any. Thus
the digital zoom implemented in connection with the device may be
understood certain kind of dynamical implementation. The size of
the cropped area of the primary image i.e. the size of the region
of interest and/or the nominal resolution of the sensor will thus
contribute to the function of the digital zooming procedure.
[0031] Owing to the invention, numerous advantages to carry out
digital zooming procedure for an image in connection with a digital
imaging device are achieved. A first advantage is achieved in the
usability of the camera device. The user has no more need for deep
knowledge concerning the digital zoom function. The user needs only
to set some size limits in the user interface of the device for
the output image and then the device itself decides the suitable
measure that is needed (if any) to get output result image desired
for the further use.
[0032] The second improvement achieved with the invention is reasonable
file size. Often, when the photocopy is intended to be produce from
the output image, there is no need to high resolution. If the intended
photocopy size is, for example, postcard size, the resolution that
is required to produce a photocopy having reasonable quality is
only something between 1-2 Mpix, for example.
[0033] Thirdly, the invention improves also the image quality in
comparison to the traditional digital zoom systems in digital cameras.
Improvement is introduced especially in mobile imaging devices that
have less memory and processing power, and that have additional
restrictions (e.g. MMS file size limitations).
[0034] Fourthly, the invention improves also the image quality
especially in a case in which the photocopy is intended to produce
from an image that is produced by a sensor having nominal resolution
below than the desired photocopy size. If the scaling measures to
the desired photocopy size is performed according to the invention,
the advantage is achieved by reducing the amount of artefacts that
would otherwise appear if the scaling measures would be performed
as post-processing after the imaging process (imaging process that
includes e.g. sharpening that should be done only once and only
after scaling) and (lossy) image compression.
[0035] The invention is particularly suitable for digital imaging
that is intended to produce such images which are intended to be
printed as photocopies. Owing to the invention a multiple consecutive
up- and downscaling operations performed for an output image are
avoided that is known from the current prior art.
[0036] Other characteristic features of the invention will emerge
from the appended Claims, and more achievable advantages are listed
in the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The invention, which is not limited to the embodiments to
be presented in the following, will be described in greater detail
by referring to the appended figures, wherein
[0038] FIG. 1 is a rough schematic view of a basic application
example of the first digital camera device and the first program
product to be arranged in connection with the first digital camera
device according to the invention,
[0039] FIG. 2 shows some examples of cropping of a primary image
in connection with the invention,
[0040] FIG. 3 shows a flowchart of the first application example
of the first method when performing digital zooming procedure,
[0041] FIG. 4 shows a flowchart of the second application example
of the first method when performing digital zooming procedure,
[0042] FIG. 5 shows a flowchart of the third application example
of the first method when performing digital zooming procedure,
[0043] FIG. 6 shows a flowchart of the fourth application example
of the first method when performing digital zooming procedure,
[0044] FIG. 7 shows a flowchart of the fifth application example
of the first method when performing digital zooming procedure,
[0045] FIG. 8 is a rough schematic view of a basic application
example of the second digital camera device and the second program
product to be arranged in connection with the second digital camera
device according to the invention,
[0046] FIG. 9 shows a flowchart of the first application example
of the second method when performing digital zooming procedure,
[0047] FIG. 10 is a rough schematic view of a basic application
example of the third digital camera device and the third program
product to be arranged in connection with the third digital camera
device according to the invention that is a combination of the devices
of FIG. 1 and FIG. 8,
[0048] FIG. 11 shows a flowchart of the application example of
the third method when performing digital zooming procedure and
[0049] FIG. 12 shows a flowchart of the application example of
the fourth method when performing digital imaging procedure.
DETAILED DESCRIPTION OF THE INVENTION
[0050] FIGS. 1, 8 and 10 show some examples of portable digital
camera devices 10.1-10.3 according to the invention. In general,
the devices 10.1-10.3 according to the invention may be, for example,
mobile devices, such as, for example, mobile phones, PDA devices
(Personal Digital Assistant) or some equivalent intelligent communication
devices ("smart device"). Of course, the devices 10.1-10.3
may also be digital cameras without any special communication features.
[0051] In their general form the devices 10.1-10.3 may include
a display 11 and image processor means 12. The display may include
a color display element 11, known as such (for, example, LCD or
TFT), or corresponding by means of which can be show and view images
OIM1-OIM3 and through which the user interface UI of the device
10.1-10.3 may be used. The display 11 may also operate as a viewfinder
which the device 10.1-10.3 may have even several (optical and digital).
In the viewfinder function, the display 11 may be used to view the
imaging view in connection with the digital imaging when the image
object is aimed with the device 10.1-10.3.
[0052] The image processor means may include one or several processor(s)
unit(s) 12 or-corresponding by means of which are carried out the
functions of the devices 10.1-10.3 in many relations. In connection
with the invention these measures are focused to the digital imaging,
more particularly to the digital zooming procedure. The devices
10.1-10.3 may also have one or more memories MEM, MEM' in which
may be store different kind of data. Some examples of these are
output images OIM1-OIM3 that are produced by the device 10.1-10.3
and also program products 30.1-30.2. The products 30.1-30.2 are
arranged in connection with the devices 10.1-10.2 in order to perform
measures and operations according to the invention.
[0053] The digital camera devices 10.1-10.3 according to the invention
have also digital zoom function 35. Digital zoom function 35 has
been used in order to form an output image OIM1-OIM3. Digital zoom
35 may be known as such but also included with the operations according
to the invention described more specifically in below.
[0054] In addition, the devices 10.1-10.3 include also imaging
means. These means may include a sensor 13 and optics 14. The sensor
13 may be known as such like the optics 14. The optics 14 may have
means to adjust focal length (optical zoom) but this is not necessary.
By using of sensor 13 and optics 14 a primary image PIM may be produce.
Also these means 13, 14 are used to produce a viewfinder image to
which cropping measures are pointed out when performing digital
zooming.
[0055] Next the devices 10.1-10.3 will be described in a manner
that is more focused to the invention. For the skilled person, it
is well known that the devices 10.1-10.3 may also include other
such functionalities, which are not required to describe in this
application context more detailed manner. In addition, the function
entities of the device 10.1-10.3 described hereinafter can, of course,
take care out of many other matters and functions that which are
considered to be relevant to describe in this connection in order
to illuminate the basic idea of the invention.
[0056] For the skilled person it is obvious that at least part
of the functions, operations and measures of the invention may be
performed in a program level executed by the processor 12. Of course,
such implementations are also possible in which at least part of
the operations are performed on program level and part of the operations
are performed on the hardware level. Next in the relevant points
are referred to these program code means by means of which the device
operations may be performed according to one embodiment.
[0057] First a reference is made to the device 10.1 presented in
FIG. 1 and digital zooming example presented in FIG. 2. The program
code means 31.1-31.10 forming the program code 31 are also presented
in FIG. 1.
[0058] As was told already in above, the device 10.1 according
to the invention includes also the display 11. By using of that
the primary image PIM produced by using the imaging means 13, 14
is arranged to be crop. Cropping operation is performed in connection
with the digital zooming procedure when the selection of the ROI1-ROI3
in the primary image PIM showed on display 11 is performed in order
to produce the output image OIM1-OIM3. The program code means 31.2
of the program code 31 may take care out of this measure.
[0059] In addition, in the user interface UI of the device 10.1
is also arranged to be set one or more settings. The expression
"user interface" is not intended to limit the invention
in any way. That may have different kind of forms, for example,
a collection(s) of buttons and/or (rotation) switches and/or only
elements presented on the display 12 which are controlled by the
control means of known kind of user interfaces or in any other suitable
manner. The settings may relate among others to the digital zooming
procedure intended to be performed. The program code means 31.1
may take care out of this measure in a well-defined manner.
[0060] The basic idea of the invention is that, for example, via
the user interface UI of the device 10.1 is arranged to be set as
the setting one or more size limit for the output image OIM1-OIM3
that is intended to be produce as the result of the digital imaging.
The program code means 31.4 may take care out of these measures.
[0061] In the invention the image processor 12 is arranged to put
a size for the output image OIM1-OIM3. That is carried out based
on the performed cropping of the primary image PIM. The size adjustment
that is defined by the size limits is performed at least in part
of the digital zoom range. The program code means 31.3 may take
care out of this measure.
[0062] More particular, the general idea of the invention is that
it puts the size for the output image OIM1-OIM3 in a smart way.
In the device 10.1 an algorithm code 31 is used that checks how
the area ROI1-ROI3 that is cropped in the primary image PIM relates
to the one or more size limits put in the UI. The size of the output
image OIM1-OIM3 is then set based on the one or more size limits
and also to the size of the cropped primary image area ROI1-ROI3.
When the image processor 12 observes that the sizes and limits set
for them relate to each other in certain manner it decides are scaling
operations needed. These scaling operations may be upscaling (being
different kind of interpolation methods) and downscaling. Scaling
operations are performed at least in part of the digital zoom range.
The digital zoom range in which the scaling operations are performed
is defined by the one or more size limits that have been set via
the user interface UI. The program code means 31.5 may take care
out of these measures. Owing to the invention the user need not
any more to select lower resolution than original_sensor_resolution
to be the output_resolution. Thus, the output_resolution is decided
in a smart way.
[0063] Next the invention is described in the case of JPEG images.
However, the invention does not exclude other image formats to be
applied but one versed in the art may adapt the invention to other
image formats too. A reference is made to the FIG. 2. That describes
different kind of cropping ROI1-ROI3 pointed out to the primary
image PIM and from which the output images OIM1-OIM3 are produced.
The reference is made to FIG. 2 when describing different method
options in the below.
[0064] Next the method in digital zooming procedure 35 in order
to form an output image OIM1-OIM3 is described in connection with
different kind of embodiments. In the first and second embodiments
only one size limits are applied in both cases. In the case of first
embodiment is referred to the FIGS. 1, 2 and to the flowchart of
the FIG. 3. The FIG. 3 is described detailed manner. The others
flowcharts are described only the parts that differs from the embodiment
of FIG. 3.
[0065] In the FIG. 3 as a first step 300 the user of the device
10.1 starts the imaging procedure according to the invention. In
stage 301 the user has an option to set one or more settings relating
to the digital zoom function 35, which is possibly needed in connection
with the imaging. These settings may be set via the device's 10.1
the user interface UI. There may be even several settings that may
be set in this stage 301, not only the setting(s) according to the
invention. The settings may be set also in that case, if the digital
zoom function is not even activated and only possible optical zooming
34 is enough perform imaging operation.
[0066] The settings that may be set in this connection are one
or more size limits for the output image OIM1-OIM3. In this embodiment
the size limit according to the invention is a minimum size min_image_size
for the output image OIM1-OIM3 that is intended to be produce in
the method. The size limit min_image_size may be expressed, for
example, as a megapixel value. Now this exemplary value may be,
for example, 1.5 Mpix. In the embodiments the sensor 13 may have
total resolution that is, for example, 5 Mpix. One should also understand
that these values hereinafter are only intended to be examples,
so they are not intended to limit the invention or its adaptation
to some special purpose.
[0067] The processor 12 registers this setting min_image_size and
stores that to the memory MEM' of the device 10.1. After this the
setting min_image_size set by the user in stage 301 may be used
always in connection with the digital imaging even if the device
10.1 would be switched off between imaging measures. So to say this
setting min_image_size may be like one of the current settings widely
used in camera devices. The setting value min_image_size may be
stored as a default value to the settings until that changes next
time by the user. These aspects relate also to other setting of
the invention described hereinafter.
[0068] The setting relating to the min_image_size and size limits
according to the invention in general may be set by using the predefined
list presented in the UI. There may be also assist information relating
to different values, which helps user in selection. In this kind
of list some minimum sizes for the output image OIM1-OIM3 may be
present in order to set one by the user. Of course, the user may
also set the size value decided by his own. Then the min_image_size
may be set to be any size. Size values may be also other values
than, for example, the integer Mpix size values. The size value
scale may change smoothly.
[0069] In stage 302 the user of the device 10.1 sights the image
objects with camera device 10.1. In stage 302 the continuous viewfinder
imaging is performed and this causes that the primary image PIM
is also produced. Because of that the primary image PIM captured
by sensor 13 and optics 14 is shown on the display 11.
[0070] If the circumstances (for example, the distance between
user and the aimed image objects) are such that the user wants to
crop the image area of the primary image PIM, he may perform zooming
procedure. If the camera device 10.1 has optical zoom function 34,
the user may utilize that in desired manner in stage 303. The optical
zoom function 34 may be adjusted to its telephoto position or to
other suitable position in order to crop the image object in a desired
manner. If telephoto position is used, the optical zoom 34 is in
its maximum level. The primary image PIM for the viewfinder 12 purpose
is then produced by using this optical zoom function 34.
[0071] If the user wants still more crop the view i.e. the region
of interest ROI1-ROI3 is in "deeper" in the primary image
PIM, he may use the digital zoom 35 of the device 10.1. This is
performed also in stage 303. The user interface UI may be designed
so that the digital zoom 35 is activated when the user tries to
zoom further than what the optical zoom 34 allows. The user may
go further from this maximum optical zoom adjustment. Also, in certain
implementations the digital zoom 35 may be activated though the
optical zoom 34 isn't its extreme telephoto position. The viewing
area ROI1-ROI3 that is cropped may be surrounded in the viewfinder
screen 11 by using, for example, a rectangular or other border as
is presented in FIG. 2. This may be used to indicate for the user
that the digital zoom 35 is activated now. The user continues the
cropping i.e. digital zooming procedure until the desired area is
reached in the viewfinder display 11.
[0072] One should be understand that only one cropping ROI1, ROI2
or ROI3 is presented in the viewfinder 11 at a time. The image objects
in the bordered area ROI1-ROI3 forms the image objects that will
come to the output image OIM1-OIM3. The surroundings area that are
outside of the borders ROI1-ROI3 will be discarded. This is well
known procedure in the digital zoom implementations.
[0073] When the border frames are around the subject in the desired
manner i.e. the region of interest ROI1-ROI3 has only the desired
image objects, the user presses the shutter button to capture the
final primary image PIM from which the device 10.1 produces the
output image OIM. The processor 12 recognizes the cropped area ROI1-ROI3
of the primary image PIM and inputs only this data to the further
processing and storing. This is performed in the stage 304.
[0074] In stages 305 and 306 is performed possible scaling operations,
which is now based on the one size limit min_image_size and also
on the size of the cropped area ROI1-ROI3 of the primary image PIM.
[0075] In stage 305 the cropped sub-images ROI1-ROI3 are taken
into the processing that is performed in the manner according to
the invention. Now the size for the output image OIM1-OIM3 that
is intended to be stored or to route further processing, for example,
at somewhere else, is put on the basis of the cropped area ROI1-ROI3
of the primary image PIM. This size adjustment may be performed
at least in part of a digital zoom range. The range, in which this
is performed, is now in this embodiment defined by the size limit
value min_image_size defined in stage 301. So, in this embodiment
the digital zooming range is divided into two sub-ranges in which
one range has been performed scaling measures and in another range
has not been performed any scaling measures.
[0076] If the processor 12 determines that the condition of stage
305 is true, i.e. the size of the cropped image area ROI1 (=1.3
Mpix) is now less than the set size limit min_image_size (=1.5 Mpix)
then the step to stage 306 is performed. Thus, the digital zoom
factor is too high that was intended in stage 301. In stage 306
the image processor 12 upscales the cropped image area ROI1 of the
primary image PIM to this minimum size min image size (=1.5 Mpix)
set for it in order to produce the final output image OIM1. The
program code means 31.6 may take care out the analyzing if the size
of cropped primary image is below the minimum size min_image_size
and the interpolating (stages 305 and 306).
[0077] However, if the size of the cropped image area ROI2, ROI3,
i.e. the digital zoom factor is such that the condition in stage
305 is untrue, this is also recognized by the processor 12, the
step to stage 307 is then performed. There the captured and cropped
image ROI2 (=2 Mpix) and ROI3 (=3 Mpix) is then stored or further
processed without any scaling measures. The program code means 31.3
performs this. So to say, the cropped image area ROI2, ROI3 without
any measures that relate to scaling, forms then the desired output
image OIM2, OIM3. Thus, the size of them will be in that case more
than minimum image size limit min_image_size set for produced output
image. The imaging procedure ends to stage 308.
[0078] The stage 307 in this embodiment and the corresponding stages
in other embodiments, too, may include the JPEG encoding process.
In the invention this JPEG coding process is performed after the
possible scaling measures. Owing to this is achieved appropriate
order to perform scaling and coding measures.
[0079] The embodiment above can be used, for example, in such case
if the user knows that he is going to print the images in certain
resolution, and he wants that the camera 10.1 does the required
interpolation. The user could also use size limit min_image_size
to make the digital zoom 35 operate in the traditional way by setting
min_image_size=max image_size, if the user so desires. The application
example of maximum image size max_image_size is described next.
[0080] In FIG. 4 is described another embodiment in which the use
of one other setting than minimum image size min_image_size is described.
In this embodiment the stages 400-404 may be equivalent with the
corresponding stages 300-304 of FIG. 3. Also, other stages, which
don't considerably differ from the performed measures of FIG. 3,
are not described hereinafter more detailed. The only exception
when considering these stages 400-404 is now that in stage 401 instead
of minimum image size min_image_size or image sizes in the sense
of invention in general, is set the maximum image size max_image_size
for the output image OIM1-OIM3 as the one or more size limits according
to the invention. This maximum image size value max_image_size may
now be, for example, 2.5 Mpix. This may also be set in the user
interface UI of the device 10.1.
[0081] The above means that the output image produced by digital
zooming procedure 35 will have the size max_image_size, between
the zoom factor [no_digital_zoom_used, max_image_size]. The final
size of the output image will be smaller than the set max_image_size
if the digital zoom is used in such amount that the size of the
cropped area is smaller than the maximum image size max_image_size
set for it.
[0082] In stage 405 the processor 12 is again used to determine
if the size of the cropped image area ROI1-ROI3 exceeds the maximum
size max_image_size (=2.5 Mpix) that was set for it in stage 401
or picked up from the memory MEM' of the digital zoom function 35.
If the condition of stage 405 is true, that it is in the case of
ROI3, the step to stage 406 is then performed.
[0083] In stage 406 the image processor 12 downscales the cropped
area ROI3 of the primary image PIM to this maximum size max_image_size
set for it. The program code means 31.7 may take care out of this
measure. Also, the downscaling methods applied herewith connection
are well apparent for the skilled person and because of that there
are no need for their detailed description.
[0084] If the condition evaluated in stage 405 is untrue, that
is now in the cases of ROI1 and ROI2, the step to stage 407 is then
performed. The size of them will remain corresponding the effective
cropped area and the output image OIM1, OIM2 has sizes 1.3 Mpix
and 2 Mpix. Other steps 407-408 may correspond the steps 307-308
described in connection with the embodiment FIG. 3.
[0085] In this embodiment the cropping stage 403 may also be optional.
If no cropping is performed in stage 403 then the captured image
PIM may also be downscale to the max_image_size. This non-cropping
feature may also be applied in other embodiments, too. If the user
wants the output images with the nominal resolution of the sensor
13 (for example, 5 Mpix), he may set in UI max_image_size=sensor_size.
[0086] In FIG. 5 is described the embodiment which mainly corresponds
the embodiment described in FIG. 4. However, this embodiment illustrates
that the data of the primary image PIM produced by sensor 13 and
optics 14 may be used to determine some imaging setups. The program
code means 31.10 may take care out of this measure.
[0087] Here in stage 502.1 this whole amount of primary image PIM
data produced by the sensor 13 is collected in order to adjust,
for example, the white balance of the final output image OIM1-OIM3.
This collection of AWB statistics may be performed in connection
with the viewfinder stage 502 in which the imaging is performed
by using sensor 13. Although, in the resulted output image OIM1-OIM3
will only have the data that is got due to the cropping procedure
i.e. the data of the region of interest ROI1-ROI3 the whole area
of the primary image PIM (=5 Mpix) captured and viewed by the sensor
13 is used to determine the AWB correction. Any kind of methods
may also be utilized in the AWB. The set of AWB will be carried
out before any possible scaling operations are performed i.e. in
this embodiment before stage 506. Of course, the other embodiments
presented above and below may also utilize the collecting of AWB
statistics performed in this embodiment.
[0088] FIG. 6 presents the embodiment in which the embodiments
described in FIG. 3 and 4 are combined to be one unified procedure.
The descriptions of these embodiments above are valid in their appropriate
parts. Here is applied as the size limits in the meaning of the
invention for the output image OIM1-OIM3 besides of the minimum
image size min_image_size in addition the maximum image size max_image_size.
[0089] These values are again set in stages 601 and 602 and they
may be in this application example the same that was used in embodiments
above (1.5 Mpix, 2.5 Mpix). This setup may also be performed in
the user interface UI of the device 10.1. In this embodiment the
area of the digital zoom factor between which the method according
to the invention is applied is after the image size of the minimum
image size (YES path of stage 606) and prior to the image size of
the maximum image size (YES path of stage 608). If the cropped image
size (ROI1, 1.3 Mpix) that the user intends to be the output image
OIM1 is determined in stage 606 to be less than the size limit min_image_size
(=1.5 Mpix) set for it upscaling i.e. interpolation measure is then
performed in stage 607. If the cropped image size (ROI3, 3 Mpix)
that the user intends to be the output image OIM3 is determined
in stage 608 to be more than the size limit max_image_size (=2.5
Mpix) set for it downscaling measure is then performed in stage
609. The program code means 31.8 may take care out of these measures
and analysis.
[0090] If the size of the cropped area ROI2 that is intended to
be the output image OIM2 is in the digital zoom factor range that
is between the maximum image size max_image_size and the minimum
image size min_image_size (i.e. NO path of stage 608) there are
not performed any measures for the cropped area ROI2 relating to
upscaling or downscaling. After storing stage 610 imaging and zooming
procedure for the image in question is ended (stage 611).
[0091] The embodiment in FIG. 7 corresponds otherwise the embodiment
presented in FIG. 6 but here also the size limits include in addition
at least one output image size output_image_size for the output
image intended to be produce. The size limit for the maximum image
size max_image_size may now be, for example, 4 Mpix and the size
limit for the minimum image size min_image_size may now be, for
example, 0.3 Mpix (=VGA resolution). The size limit for the output
size limit output_image_size may now be in this exemplary case,
for example, 3.2 Mpix. Alternatively, this output size limit may
also be a set of some general used resolutions (for example, 4 Mpix,
3.2 Mpix, 2 Mpix, 1 Mpix). In this embodiment the nominal resolution
of the sensor 13 may be, for example, 5 Mpix. Owing to this embodiment
the user will achieve only such output images which size would be
just desired. The program code means 31.9 may take care out of operations
relating to this output image size measure set.
[0092] According to a first aspect of this embodiment, if such
a setup is performed for the size limits that the minimum image
size min_image_size is set to be very small, for example, 0.3 Mpix,
and the maximum image size max_image_size is set to be very large,
for example, 5 Mpix, all images are then generated to the set output
image size output_image_size 3.2 Mpix.
[0093] The size limit setting for the output image size output_image_size
may be now set in stage 702'. If the predefined set of the output
image size limits (for example, 4 Mpix, 3 Mpix, 2 Mpix, 1 Mpix)
are applied, then in this stage 702' it is possible to select a
special imaging mode relating to digital zoom function 35 that is
now expressed as a "quantized output size mode". In general,
this in mode the digital zoom range between the set minimum size
limit min_image_size and the set maximum size max_image_size limit
is quantized by the set output image size limits on the basis of
which is set the size for the cropped primary image in an established
manner. According to this mode the user don't need to set every
image sizes between size limits max_image_size and min_mimage_size
that he or she desires but the image is scaled to one of the predefined
image size based on an established criteria. This selection reduces
the amount of selections needed to perform in the user interface
UI.
[0094] If in stage 708 is determined by processor 12 that the cropped
size i.e. the size of the region of interest ROI2 of the produced
primary image PIM is between the size limits min_image_size and
max_image_size then a step to stage 709.2 is performed. There the
image processor 12 scales the cropped area ROI2 (=2 Mpix) of primary
image PIM to the set output image size output_image_size. This scaling
measure is performed in an established manner.
[0095] The scaling measure may be implement to be in such a manner,
for example, that between the size range (3.2-4] Mpix the size of
the output image is to be 4 Mpix and between the size range (2-3.2]
Mpix the size of the output image is to be 3.2 Mpix and between
the size range (1-2] Mpix, that is the case in ROI2 the size of
the output image is to be 2 Mpix etc. In these cases the cropped
primary image is thus interpolated. Of course, the implementation
may also be instead for the presented above i.e. instead of the
interpolation the decimation would be performed as a scaling measure.
In such a embodiment, for example, the cropped primary image between
the size range (3.2-4] Mpix would be decimated to be 3.2 Mpix etc.
This quantization embodiment allows to produce such output images
which don't have arbitrary sizes but the size that is the most common
size being nearest for the cropped image area.
[0096] So, in this stage 709.2 both the downscaling and also the
upscaling measures are possible to be performed which depends on
the relation of the size of ROI and output_image_size and also the
implementation of this quantization embodiment. Otherwise the procedure
may be mainly carried out like in the embodiments described above.
It should also be noticed in connection with this embodiment of
FIG. 7 that if the size of the cropped image area is precisely the
size set for the size limits, i.e, max_image_size or min_image_size,
then the stages 707 and 708 are performed without any interpolation
or decimation measures.
[0097] Of course, such an embodiment is also possible, in which
there are not applied the size limits relating to maximum and minimum
size but only the set size for all output images that are intended
to be produce. In that case the measures, which are carried out
may depend on the sizes of the regions of interests ROI1-ROI3. If
size of the cropped area i.e. in cases of ROI1 and ROI2 goes below
the set size for the output image then is performed interpolation
measures i.e. new pixels are created in a well-known manner. If
size of the cropped area i.e. in the case of ROI3 exceeds the set
size for the output image then is performed downscaling measures.
Of course, if the size of the cropped area would be just precisely
the size of the set output size then no measures are required. This
is obvious for the other embodiments, too.
[0098] In FIG. 8 is described another embodiment of the device
10.2 according to the invention. Mainly the functional entities
of that have been defined in appropriate level in connection with
the description of FIG. 1. The device 10.2 is equipped with a program
code 32 that may take care out of the required operations.
[0099] Also, in this embodiment the digital camera device 10.2
has functionality in order to carry out digital zoom function. This
is intended to form an output image. The device 10.2 includes besides
the functions and entities described in connection of FIG. 1 also
a user interface entity UI and processor entity 12. In the user
interface UI the primary image produced by sensor 13 is cropped
in connection with the digital zooming procedure in order to form
the output image. This may take care out of by program code means
32.1. The image processor 12 stores the output image by using a
quality factor qf set for it. This may take care out of by program
code means 32.2.
[0100] In the device 10.2 according to the invention, the quality
factor qf is surprisingly connected to the size of the cropped primary
image area i.e. to the size of the region of interest about which
the final output image is intended to be produced.
[0101] The measures relating to this may take care out of by program
code means 32.3.
[0102] In FIG. 9 is described one example of the method in digital
zooming procedure in order to form an output image. This method
may be implement by using the device 10.2 described in FIG. 8. Here
the stages 900-902 may correspond measures already described in
the embodiments presented prior to this embodiment. These stages
may include viewfinder imaging (stage 901), cropping of the viewfinder
image (stage 902) and capturing the cropped image in order to produce
the output image (stage 903).
[0103] After stage 903 is performed stage 904 in which the quality
factor qf is determined for the captured and cropped image. The
quality factor qf is now determined surprisingly on the basis of
the size of the cropped image area. The sizes may be, for example,
megapixel values, as presented already in embodiments above. Thus,
the size may be understood as resolution of the image. This procedure
is carried out, for example, in such a manner that by processor
12 is first determined the size of the cropped image area.
[0104] The quality factor may be calculated, for example, by using
the equation of:qf_new=qf_old+({1.0-scale}*{max[96, qf_old]-qf_old}).
[0105] In thatscale=(crop.sub.--xsize/original.sub.--xsize)*(crop.sub.--ys-
ize/original.sub.--ysize).
[0106] In that qf_new=new quality factor, qf_old=old quality factor,
crop_xsize=size of ROI in vertical direction crop_ysize =size of
ROI in horizontal direction and original_xsize, original_ysize=size
of primary image produced by sensor in the horizontal and in the
vertical direction. The device 10.2 may be equipped with the program
code means 32.4 that takes care out of these calculations. The file
size of the cropped image is smaller than the file size of the cropped
and interpolated image, even if the JPEG quality factor qf is increased
considerably for the cropped image.
[0107] In stage 905 the captured and cropped output image is stored
using a quality factor set for it (program code means 32.2).
[0108] The applying of the quality factor qf in connection with
JPEG coding is obvious for the man skilled in the art. As is known,
the JPEG encoding bases on 8.times.8 discrete cosine transform (DCT).
The quality factor qf is used to adjust the values of the quantizing
matrix that is after DCT conversion (=64 values). The quantizing
matrix may be calculated prior to the coding by using of the value
of the quality factor qf.
[0109] When the values of the divisors being stored in the matrix
grows that cause the greater portion of the values of the DCT quantizes
to zero. This causes that the size of the output image to be stored
decreases and in same time the quality becomes poorer. In the application
embodiment described above the greater value of the quality factor
qf (near to 100) means the lesser values for the divisors in the
matrix. This causes better quality for the image. When the value
of the quality factor approach zero the values of the divisors becomes
greater. The effect in the quality of the output image is opposite.
[0110] In some image processing softwares the quality factor is
defined by using the name of "compressing factor". In
these cases the function is right contrary. One should also understood
that to the JPEG file in connection with the image data is always
stored also the used quantisizing matrix, not the actual quality
factor qf at all. Afterwards, by using of the quantisizing matrix
the used quality factor qf may then be estimated. The JPEG standard
presents certain basic matrix which represents quality factor value
qf=50. However, if the user wants to select his matrix on some other
manner that is also possible, of course.
[0111] The quality factor qf=100 means that all divisor values
of the matrix are one and thus DCT converted value are cut off to
the integer precision (in that case the image is compressed a little
bit).
[0112] If the whole process is described block by block: From the
image is taken 8.times.8 image block.fwdarw.DCT conversion is pointed
out to the image block.fwdarw.the converted values are quantisized
by using of the quantisizing matrix.fwdarw.the quantisized values
are coded by using of the zigzag scanning and variable length coding.
Nevertheless, the basic theory of the JPEG processes are apparent
for the man skilled in the art and this background information presented
above is not intended to be limit the methods according to the invention
in any manner. In general, the JPEG processing steps are included
to the stages 307 (and other corresponding storing stages in the
other embodiments).
[0113] The quality factor qf is the input parameter for the JPEG
encoder when the output image intended to be stored is compressed
to JPEG format. If the JPEG compression quality factor qf is not
increased for the cropped images, the compression artifacts might
become disturbing if the image is later interpolated into considerably
bigger resolution.
[0114] In FIG. 10 has been described a third example of the device
10.3 according to the invention and in FIG. 11 a flowchart relating
to this device 10.3. Now the methods and devices 10.1, 10.2 are
combined to be one unified device 10.3. If crystallizing the combined
embodiments above and the idea of FIG. 11 the JPEG quality factor
qf is thus connected to the crop size of the ROI1-ROI3. Smaller
crop size of the ROI allows higher quality factor qf (less compression)
to be set and still have smaller file size. The actual image details
are preserved better when using cropping, no interpolation and higher
quality factor, in comparison to cropping, interpolation and lower
quality factor.
[0115] If the image is interpolated into bigger resolution afterwards,
the JPEG-compression artefacts will not become as visible as in
a case in which the JPEG quality factor is static, because there
will be less JPEG compression artefacts due to increased quality
factor. One skilled in the art may also combine the embodiments
of FIG. 7 and 11, however without excluding the other embodiment
combinations.
[0116] Yet according to one embodiment the size limits according
to the invention and presented above need not necessary be equal
or smaller than the nominal resolution of the sensor 13 by using
of which the primary image PIM is produced with cooperation of the
optics 14. The only conditions for the minimum and maximum size
limits according to the invention are that 1) min_image_size<=max_image_size
and 2) min_image_size>0.
[0117] One example of this kind of embodiment may be the situation
in which the user wants to perform digital imaging with his or her
camera device in order to prepare hardcopies from the produced digital
images by using the image printer device. This embodiment is presented
as a flowchart in FIG. 12. If the nominal resolution of the sensor
13 of the camera device would be, for example, 0.3 Mpix (=VGA resolution)
and the default printing size of the image printer device would
be, for example, 1375664 pix then, according to the first embodiment,
the whole primary image area may be interpolated from 0.3 Mpix to
1375664 pix that is now set to be max_image_size and min_image_size
(stage 2100). Owing to the embodiment the images produced by VGA
sensor 13 are able to be fitted precisely to the image printer device.
Thus, in this embodiment the cropping process isn't necessarily
performed at all but whole of the sensor data captured in stage
2200 is interpolated in stage 2400 from the nominal sensor resolution
to the precisely image size being characteristic of the image printing
device. This is performed if the size condition of stage 2300 is
fulfilled which means that the nominal resolution of the sensor
13 is smaller than the min_image_size set to be used in this connection.
[0118] Other universal stages 2000, 2500, 2600 were described already
above embodiments. Of course, according to a second embodiment,
one versed in the art may apply this kind embodiment to the embodiments
presented already above in FIGS. 3-7, 9 and 11 in which the cropping
process were performed.
[0119] In the embodiment above, in which the size limits are equal
or greater than the nominal sensor resolution and no cropping is
performed at all, a reference is made to the device 10.3 presented
in FIG. 10. There is also a program product 33 having code means
to perform scaling measures according to this embodiment. Code means
may mainly correspond the code means 31.1-31.10 in connection with
FIG. 1 but now tailored to the concerned embodiment. If cropping
is not performed, the display 11 is only intended to be viewfinder
and possible interface for the user interface UI. 11. There the
image processor 12 performs scaling operations for the primary image
in order to produce the output image having the size of the set
size setting. Thus, one versed in the art recognizes that all combinations
between different embodiments presented in connection with this
application are possible.
[0120] The motivation for the embodiments above arises from the
reason, for example, that the user may want to prepare hardcopies
having the size, for example, 4''.times.6'' and the resolution 254
dpi and the user also wants that the digital camera device 10.3
performs the interpolation processing. The advantage that is achieved
by this is that the interpolation is now carried out, among others,
before the sharpening and the JPEG-encoding. This avoids the magnification
of the sharpening and JPEG artefacts, and produces better sharpening
result. Thus, these embodiments remove the need for the post-processing
of the image intended to be printed that would otherwise be performed
by the digital printing service in which the cropped or noncropped
VGA image would be interpolated to the size of 1.38 Mpix before
printing process, for example. Interpolating the image after JPEG-encoding
would magnify thus the artefact effects.
[0121] In FIGS. 1, 8 and 10 is presented rough schematic views
of application examples of a program products 30.1, 30.2 according
to the inventions. The program products 30.1, 30.2 are intended
to perform in connection with digital zoom function 35 in order
to form an output image in a digital camera device 10.1-10.3 according
to the invention. The program products 30.1, 30.2 may include a
storing means, such as, a memory medium MEM and also a program codes
31, 32, 33 executable by the processor unit 12 of the devices 10.1-10.3
and written in the memory medium MEM for dealing out digital zooming
procedure in accordance with the methods of the invention at least
partly in the software level. The memory medium MEM for the program
codes 31, 32 may be, for example, a static or dynamic application
memory of the device 10.1-10.3, wherein it can be integrated directly
in connection with the imaging application or more specifically
in connection with the digital zoom function 34.
[0122] The program codes 31, 32, 33 may include several code means
31.1-31.10, 32.1-32.4 described above, which can be executed by
processor 12 and the operation of which can be adapted to the method
descriptions just presented above. The code means 31.1-31.10, 32.1-32.4
may form a set of processor commands executable one after the other,
which are used to bring about the functionalities desired in the
invention in the equipment 10.1-10.3 according to the invention.
The invention does not have major impact on the implementation details
of digital zoom function 35. The implementation details depend on
the product.
[0123] When considering the basic idea of the invention after the
digital zoom function 35 is activated, the original image PIM produced
by sensor and optics 13, 14 is cropped according to the digital
zoom factor. It doesn't matter that the resolution of the output
image OIM1-OIM3 gets smaller due to cropping, because no additional
real information would be introduced by the interpolation or upscaling
measures anyway. It makes no sense, especially in mobile communication
devices (cf. 100 kB file size limitations of MMS (Multimedia Messaging
Service)), to interpolate into bigger image (=bigger file size)
from the cropped image. Sending the image, opening/processing of
the image etc. are faster with the cropped image. For sending and
receiving images the devices 10.1-10.3 may include communication
modules in order to communicate in network system (not shown). The
image can be interpolated into bigger resolution, afterwards, if
it is required for some reason, for example, the embodiment relating
to quality factor.
[0124] Some of the advantages are explained already in description
above. Here are presented some real situations and achieved advantages,
which may appear during the use of the digital imaging product 10.1-10.3.
EXAMPLE 1
[0125] The photo print service company X uses 254 dpi printing
resolution (typical at the moment of filing). User wants to take
pictures with his 4 Mpix digital camera device and have postcard
size (10.times.15 (=4''.times.6'')) printouts of them from this
photo service X. Now, the user actually needs .about.1 Mpix images
and not 4 Mpix images, because the image files will be downscaled
to .about.1 Mpix size anyway in the photo service before printing.
The accurate size for the image having postcard size (10.times.15)
is 4.times.254.times.6.times.254=1548384 pix and for the image having
postcard size (10.times.13) is 4.times.254.times.4.times.254.times.4/3=996.times.1354=1375664
pix. These exact sizes are cited above .about.1 Mpix. The user sets
max_image_size to 4 Mpix and min_image_size to 1548384 pix or 1375664
pix, and can use digital camera 10.1 normally. It would not be wise
to use the traditional approach, in which the cropped image is interpolated
back to original resolution, and then the image is again downscaled
before printing. Interpolating/downscaling back and forth deteriorates
the image quality.
[0126] From the viewpoint of UI convenience it is also possible
to set in the user interface UI the DPI value and the size of the
photocopy intended to be print instead of the sizes calculated above.
In this kind of UI implementation the user is not required to determine
the exact pixel values described above. Also, if the user knows
at the moment of digital imaging that he or she is going to utilize
only the photo service X for producing hardcopies then it is useful
to set max_image_size=min_image_size.
EXAMPLE 2
[0127] Advanced users can have better control over the digital
zoom operation (use of interpolation), and at the same time normal
users don't have to know anything more about digital zoom than with
any other approach.
EXAMPLE 3
[0128] User does not need to lower the target resolution when he
wants to use smarter digital zoom (like in prior art solutions,
for example), output resolution will be decreased automatically
when digital zoom factor is bigger than x1.
EXAMPLE 4
[0129] Very big digital zoom does not cause the image to be cropped
into very small image like may be the situation in some prior art
solutions, but user can set lower limit for the resolution, e.g.
according to desired printing resolution.
EXAMPLE 5
[0130] The fact that JPEG quality factor is connected to the digital
zoom factor (=cropping factor) improves the image quality.
EXAMPLE 6
[0131] The cropped images are faster to process/send than the interpolated
images, especially in mobile communication devices. The user can
zoom into the cropped image later in some suitable tool (the "Media
Gallery") by using e.g. bicubic interpolation, it is not restricted
by the invention.
[0132] It should be understood that the above specification and
the figures relating to it are only intended to illustrate the present
invention. Thus, the invention is not limited only to the embodiments
presented above or to those defined in the claims, but many various
such variations and modifications of the invention will be obvious
to the professional in the art, which are possible within the scope
of the inventive idea defined in the appended claims.
REFERENCES
[0133] [1]: http://www.docs.sony.com/release/DSCF828revision.pdf,
WEB downloading possible at least May 18, 2005; [0134] [2]: http://h10032.www1.hp.com/ctg/Manual/bpy60657.pdf,
WEB downloading possible at least May 18, 2005; |