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Digital Camera Patent Abstract
A digital camera system with an image sensing device, wlhich includes
an image sensing device, a converter, an image processor and a universal
serial bus (USB) transceiver. The image sensing device receives
light to capture an analog image signal. The converter is connected
to the image sensing device to convert the analog image signal into
a digital image. The image processor is connected to the converter
to perform a special image processing on the digital image to thus
produce a processed image. The USB transceiver is connected to the
image processor to send the processed image to a host and receives
digital camera parameters sent by the host.
Digital Camera Patent Claims
1. A digital camera system with an image sensing device, comprising:
an image sensing device, which receives light to capture an analog
image signal; a converter, which is connected to the image sensing
device to convert the analog image signal into a digital image;
an image processor, which is connected to the converter to perform
an image processing on the digital image to thus produce a processed
image; and a universal serial bus (USB) transceiver, which is connected
to the image processor to send the processed image to a host and
receives digital camera parameters sent by the host.
2. The system as claimed in claim 1, further comprising: a controller,
which is connected to the USB transceiver to set the image sensing
device and the image processor according to the digital camera parameters
sent by the host or default digital camera parameters stored in
the controller.
3. The system as claimed in claim 1, wherein the image sensing
device is a complementary metal oxide semiconductor (CMOS) image
sensing device.
4. The system as claimed in claim 1, wherein the converter comprises:
an automatic gain controller (AGC), which is connected to the image
sensing device to adjust the analog image signal; and an analog
to digital converter (ADC), which is connected to the AGC to convert
the analog image signal adjusted into a digital signal to thus obtain
the digital image.
5. The system as claimed in claim 4, wherein the image processor
comprises: an interpolator, which is connected to the ADC to perform
an interpolation on the digital image to thus produce an interpolated
digital image; an exposure device, which is connected to the interpolator
to perform an exposure correction on the interpolated digital image
to thus produce an exposed digital image; an automatic white balance
device, which is connected to the exposure device to perform a white
balance correction on the exposed digital image to thus produce
a white balance digital image; and a gamma corrector, which is connected
to the automatic white balance device to perform a gamma correction
on the white balance digital image.
6. The system as claimed in claim 2, wherein the USB transceiver
comprises: a first-in first-out (FIFO) buffer, which is connected
to the image processor to temporarily store image data output by
the image processor; a USB data and control switch, which has one
terminal connected to the FIFO buffer to receive data output by
the FIFO buffer and the other terminal connected to the controller
to transmit the parameters to the controller; and a USB interface,
which is connected to the USB data and control switch to receive
and transmit data to the host.
7. A digital camera system with an image sensing device, comprising:
an image sensing device, which receives light to capture an analog
image signal; a converter, which is connected to the image sensing
device to convert the analog image signal into a digital image;
an image processor, which is connected to the converter to perform
an image processing on the digital image to thus produce a processed
image; an RGB to YUV converter, which is connected to the image
processor to convert the processed image from an RGB to a YUV mode
to thus produce a YUV image; and a USB transceiver, which is connected
to the RGB to YUV converter to send the YUV image to a host and
receives digital camera parameters sent by the host.
8. The system as claimed in claim 7, further comprising: a controller,
which is connected to the USB transceiver to set the image sensing
device and the image processor according to the digital camera parameters
sent by the host or default digital camera parameters stored in
the controller.
9. The system as claimed in claim 7, wherein the image sensing
device is a complementary metal oxide semiconductor (CMOS) image
sensing device.
10. The system as claimed in claim 7, wherein the converter comprises:
an automatic gain controller (AGC), which is connected to the image
sensing device to adjust the analog image signal; and an analog
to digital converter (ADC), which is connected to the AGC to convert
the analog image signal adjusted into a digital signal to thus obtain
the digital image.
11. The system as claimed in claim 10, wherein the image processor
comprises: an interpolator, which is connected to the ADC to perform
an interpolation on the digital image to thus produce an interpolated
digital image; an exposure device, which is connected to the interpolator
to perform an exposure correction on the interpolated digital image
to thus produce an exposed digital image; an automatic white balance
device, which is connected to the exposure device to perform a white
balance correction on the exposed digital image to thus produce
a white balance digital image; and a gamma corrector, which is connected
to the automatic white balance device to perform a gamma correction
on the white balance digital image.
12. The system as claimed in claim 8, wherein the USB transceiver
comprises: a first-in first-out (FIFO) buffer, which is connected
to the image processor to temporarily store image data output by
the image processor; a USB data and control switch, which has one
terminal connected to the FIFO buffer to receive data output by
the FIFO buffer and the other terminal connected to the controller
to transmit the parameters to the controller; and a USB interface,
which is connected to the USB data and control switch to receive
and transmit data to the host.
13. A digital camera system with an image sensing device, comprising:
an image sensing device, which receives light to capture an analog
image signal; a converter, which is connected to the image sensing
device to convert the analog image signal into a digital image;
an image processor, which is connected to the converter to perform
an image processing on the digital image to thus produce a processed
image; an RGB to YUV converter, which is connected to the image
processor to convert the processed image from an RGB to a YUV mode
to thus produce a YUV image; a USB transceiver, which is connected
to the RGB to YUV converter to send the YUV image to a host and
receives digital camera parameters sent by the host; and a sound
encoder, which is coupled to the USB transceiver to code an analog
audio signal and to send the audio signal coded to the host through
the USB transceiver.
14. The system as claimed in claim 13, further comprising: a controller,
which is connected to the USB transceiver to set the image sensing
device and the image processor according to the digital camera parameters
sent by the host or default digital camera parameters stored in
the controller.
15. The system as claimed in claim 13, wherein the image sensing
device is a complementary metal oxide semiconductor (CMOS) image
sensing device.
16. The system as claimed in claim 13, wherein the converter comprises:
an automatic gain controller (AGC), which is connected to the image
sensing device to adjust the analog image signal; and an analog
to digital converter (ADC), which is connected to the AGC to convert
the analog image signal adjusted into a digital signal to thus obtain
the digital image.
17. The system as claimed in claim 16, wherein the image processor
comprises: an interpolator, which is connected to the ADC to perform
an interpolation on the digital image to thus produce an interpolated
digital image; an exposure device, which is connected to the interpolator
to perform an exposure correction on the interpolated digital image
to thus produce an exposed digital image; an automatic white balance
device, which is connected to the exposure device to perform a white
balance correction on the exposed digital image to thus produce
a white balance digital image; and a gamma corrector, which is connected
to the automatic white balance device to perform a Gamma correction
on the white balance digital image.
18. The system as claimed in claim 13, wherein the USB transceiver
comprises: a first-in first-out (FIFO) buffer, which is connected
to the image processor to temporarily store image data output by
the image processor; a USB data and control switch, which has one
terminal connected to the FIFO buffer to receive data output by
the FIFO buffer and the other terminal connected to the controller
to transmit the parameters to the controller; and a USB interface,
which is connected to the USB data and control switch to receive
and transmit data to the host.
Digital Camera Patent Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a CMOS digital camera system and,
more particularly, to a digital camera system with an image sensing
device.
[0003] 2. Description of Related Art
[0004] In general, a typical digital camera can be the type of
charge coupled device (CCD) and complementary metal oxide semiconductor
(CMOS) according to its internal image sensing device. Since a CMOS
image sensing device has the pixel structure more complicated than
a CCD but its light sensing opening is smaller than that of the
CCD, when comparing CCD image sensing device with the CMOS one of
the the same size, the CCD image sensing device has a resolution
higher than the CMOS image sensing device. Accordingly, the CMOS
image sensing device is widely used in low-class products.
[0005] FIG. 1 is a block diagram of a typical CMOS digital camera
100, which consists of a CMOS image sensing device 110, a sensing
device interface 120, an image data compressor 130, a serial interface
150, a controller 160 and a USB interface 140. As shown in FIG.
1, the CMOS image sensing device 110 receives light to capture an
image signal. The sensing device interface 120 receives an image
sent by the CMOS image sensing device 110. The image data compressor
130 compresses an original image received and sends the compressed
image to a host (not shown) through the USB interface 140.
[0006] After the compressed image sent by the USB interface 140
is received, the host decompresses it and performs associated processing
for displaying the image on the screen. If the CMOS image sensing
device 110 has a higher resolution, the host needs more processing
time and higher computational capability for rapidly displaying
an image on the screen. However, this increases the load of the
host and influences the display speed of the CMOS digital camera
on the host. Therefore, it is desirable to provide an improved CMOS
digital camera to mitigate and/or obviate the aforementioned problems.
SUMMARY OF THE INVENTION
[0007] The object of the invention is to provide a digital camera
system with an image sensing device, which can perform image processing
to thus reduce the processing time and computational capability
of a host and rapidly display an image on the screen.
[0008] According to a feature of the invention, a digital camera
system with an image sensing device is provided. The system includes
an image sensing device, a converter, an image processor and a universal
serial bus (USB) transceiver. The image sensing device receives
light to capture an analog image signal. The converter is connected
to the image sensing device to convert the analog image signal into
a digital image. The image processor is connected to the converter
to perform a special image processing on the digital image to thus
produce a processed image. The USB transceiver is connected to the
image processor to send the processed image to a host and receives
digital camera parameters sent by the host.
[0009] According to another feature of the invention, a digital
camera system with an image sensing device is provided. The system
includes an image sensing device, a converter, an image processor,
an RGB to YUV converter and a universal serial bus (USB) transceiver.
The image sensing device receives light to capture an analog image
signal. The converter is connected to the image sensing device to
convert the analog image signal into a digital image. The image
processor is connected to the converter to perform an image processing
on the digital image to thus produce a processed image. The RGB
to YUV converter is connected to the image processor to convert
the processed image from an RGB to a YUV mode to thus produce a
YUV image. The USB transceiver is connected to the RGB to YUV converter
to send the YUV image to a host and receives digital camera parameters
sent by the host.
[0010] According to a further feature of the invention, a digital
camera system with an image sensing device is provided. The system
includes an image sensing device, a converter, an image processor,
an RGB to YUV converter, a universal serial bus (USB) transceiver
and a sound encoder. The image sensing device receives light to
capture an analog image signal. The converter is connected to the
image sensing device to convert the analog image signal into a digital
image. The image processor is connected to the converter to perform
an image processing on the digital image to thus produce a processed
image. The RGB to YUV converter is connected to the image processor
to convert the processed image from an RGB to a YUV mode to thus
produce a YUV image. The USB transceiver is connected to the RGB
to YUV converter to send the YUV image to a host and receives digital
camera parameters sent by the host. The sound encoder is connected
to the USB transceiver to code an analog audio signal and to send
the audio signal coded to the host through the USB transceiver.
[0011] Other objects, advantages, and novel features of the invention
will become more apparent from the following detailed description
when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a block diagram of a typical CMOS digital camera;
[0013] FIG. 2 is a block diagram of a digital camera system with
an image sensing device according to the invention;
[0014] FIG. 3 is a schematic view of sensing pixels of a CMOS image
sensing device according to the invention;
[0015] FIG. 4 is a block diagram of an embodiment according to
the invention; and
[0016] FIG. 5 is a block diagram of another embodiment according
to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] FIG. 2 is a block diagram of a digital camera system with
an image sensing device according to the invention. In FIG. 2, the
system includes an image sensing device 210, a converter 220, an
image processor 230, a universal serial bus (USB) transceiver 240
and a controller 250. The image sensing device 210 is a complementary
metal oxide semiconductor (CMOS) image sensing device to receive
light to thus capture an analog image signal. The converter 220
is connected to the image sensing device 210 to convert the analog
image signal into a digital image.
[0018] The image processor 230 is connected to the converter 220
to perform an image processing on the digital image to thus produce
a processed image. The USB transceiver 240 is connected to the image
processor 230 to send the processed image to a host (not shown)
and to receive digital camera parameters sent by the host. The controller
250 is connected to the USB transceiver 240 to set the image sensing
device 210 and the image processor 230 according to the parameters
sent by the host or default digital camera settings stored in the
controller.
[0019] The converter 220 includes an automatic gain controller
(AGC) 221 and an analog-to-digital converter (ADC) 222. The AGC
220 is connected to the image sensing device 210 to adjust a gain
of the AGC 221 according to a control signal produced by the controller
250 and to further adjust an analog image signal output by the image
sensing device 210 such that the analog image signal adjusted meets
with an input range of the ADC 222, thereby obtaining an optimal
image signal. The ADC 222 is connected to the AGC 221 to convert
the analog image signal adjusted into a digital signal, thereby
obtaining a digital image.
[0020] The image processor 230 includes an interpolator 231, an
exposure device 232, an automatic white balance device 233 and a
gamma corrector 234. The interpolator 230 is connected to the ADC
222 to interpolate the digital image. As shown in FIG. 3, pixel
310 only has green color, and thus the interpolator 231 is employed
to produce red and blue colors using pixels around the pixel 310,
such that the pixel 310 can have the three primary colors of green,
read and blue, and performs the same processing on the remaining
pixels. Thus, an image sensed by the CMOS image sensing device 210
is interpolated by the interpolator 231 to thus obtain an image
with each pixel containing red, green, and blue colors (briefly,
an interpolated digital image).
[0021] The exposure device 232 is connected to the interpolator
230 to perform an exposure correction on the interpolated digital
image. The exposure correction determines the environment of a current
photographer by an exposure metering to thus find optimal exposure
parameters. When a light hits the CMOS image sensing device 210
through a lens to thus produce charges. The converter 220 converts
an analog signal into a digital signal. The exposure device 232
measures the exposure intensity over the entire or partial frame
to obtain a measured value. The controller 250 adjusts the exposure
parameters based on the measured value and further adjusts the gain
of the AGC 221 to thus obtain a best exposure amount.
[0022] The white balance device 233 is connected to the exposure
device 232 to perform a white balance correction on the digital
image after the exposure. The gamma corrector 234 is connected to
the automatic white balance device 233 to perform a gamma correction
on the digital image after the white balance correction. The gamma
correction is performed to compensate a non-linearity feature of
the CMOS image sensing device 210, which is caused by a non-linearity
relation between an input light amount of the sensing components
(pixels) of the CMOS image sensing device 210 and its corresponding
output voltage.
[0023] The USB transceiver 240 includes a first-in first-out (FIFO)
buffer 241, a USB data and control switch 242 and a USB interface
243. The FIFO buffer 241 is connected to the image processor 230
to temporarily store the image data output by the image processor
230. In this case, the FIFO buffer 241 is a single-port FIFO buffer.
[0024] The USB data and control switch 242 has one terminal connected
to the FIFO buffer 241 to receive output data by the FIFO buffer
241 and the other terminal connected to the controller 250 to transmit
the parameters to the controller 250. The USB interface 243 is connected
to the USB data and control switch 242 to receive and transmit data
to the host.
[0025] FIG. 4 is a block diagram of an embodiment according to
the invention. This embodiment is similar to that shown in FIG.
2, except that an RGB to YUV converter 460 is provided between the
image processor 430 and the USB transceiver 440. The RGB to YUV
converter 460 is connected to the image processor 430 to convert
the processed image from an RGB to a YUV mode to thus produce a
YUV image and send it to a host (not shown) for further processing
through the USB transceiver 440. As such, the host can directly
compress the YUV image to obtain a compressed YUV image, i.e., a
typical JPEG image and save the RGB to YUV conversion.
[0026] FIG. 5 is a block diagram of another embodiment according
to the invention. This embodiment is similar to that shown in FIG.
4, except that a sound encoder 570 is provided. The sound encoder
570 is connected to the USB transceiver 440 to receive an analog
audio signal produced by a microphone (not shown) for coding and
to send the audio signal coded to the host through the USB transceiver
540.
[0027] As cited, since the transmission speed of the USB interface
is getting higher and higher, there is almost no influence on the
transmission bandwidth of the USB interface for an image data amount
with compression or not. Accordingly, a host load is relatively
reduced when receiving an image that does not require being decompressed
and performed with operations such as interpolation, exposure correction,
automatic white balance correction and gamma correction. In addition,
since the operations are performed in the CMOS digital camera, the
gain of the AGC can be adjusted by referring to the results performed
and the parameters set by the host. Thus, the analog image signal
adjusted can meet with the input range of the ADC, and accordingly
an optimal image signal is obtained.
[0028] Although the present invention has been explained in relation
to its preferred embodiment, it is to be understood that many other
possible modifications and variations can be made without departing
from the spirit and scope of the invention as hereinafter claimed.
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