JP2003299005A - Image processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing system with reduced load on a digital camera in image processing. <P>SOLUTION: From a picture photographed with a digital camera 2, a 12-bit CCD-RAW data is generated after performing analog-to-digital conversion of an analog signal obtained by a CCD image sensor. By preprocessing the 12-bit CCD-RAW data, an 8-bit CCD-RAW data of reduced data quantity is generated, and then transmitted to an image processing server 3 through the Internet 4. The image processing server 3 performs both image quality calibration processing and YC processing onto the 8-bit CCD-RAW data, to obtain a YCbCr image data. Next, fixed-length processing and compression processing are performed on the obtained YCbCr image data, followed by file conversion, and thus a JPEG image data is generated. The JPEG image data is transmitted to the digital camera 2 through the Internet. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of an image processing system using a digital camera and an image processing server.

[0002]

2. Description of the Related Art In a digital camera, image data in jpeg format is used as a standard file format. The image data in jpeg format is CCD-RA obtained by digitizing an analog signal obtained from a CCD image sensor.
The W data is formed by performing gamma correction, offset setting, gain setting, bit reduction processing, YC processing, fixed length processing, compression processing, file conversion processing, and the like.

In a conventional digital camera, image data in the jpeg format is created by an image processing circuit in the digital camera. The number of pixels of CCD image sensors is increasing, and the image data is also increasing in capacity. In particular, a CCD of a CCD image sensor arranged in a honeycomb
-RAW data has a double data capacity after YC processing. Therefore, high-performance C for quick image processing
PUs, DSPs, large-capacity image memories, etc. are required in digital cameras.

[0004]

High-performance CPU and DS
P, the large-capacity image memory is a factor of increasing the cost of the digital camera. Therefore, many methods have been invented to reduce the load on image processing in a digital camera.

For example, in the invention described in Japanese Patent Laid-Open No. 2001-209132, image data is input to a client computer, the image data is transmitted from the client computer to an image processing server, and the image processing server performs image processing. The image data subjected to the image processing is transmitted from the image processing server to the client computer.

However, the above invention is troublesome because the image data cannot be sent to the image processing server unless the image data is input from the digital camera to the client computer. There is also a problem that the image data that has been optimally image-processed cannot be obtained only by the digital camera, so that it cannot be used by a user who does not have a computer.

An object of the present invention is to solve the above problems, and an object thereof is to provide an image processing system in which the load of the digital camera on the image processing is reduced.

[0008]

In order to solve the above problems, the image processing system of the present invention comprises a digital camera for photographing and an image processing server for performing image processing. In the digital camera, the image data is reduced in bit rate and transmitted to the image processing server, and the image processing server subjects the image data to YC processing, fixed length processing and compression processing, and then returns it to the digital camera. .

Further, it is preferable to display the photographed image on the image display means of the digital camera by utilizing the low bit image data. Furthermore, the image processing server may perform image quality correction processing on the low bit image data.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual diagram showing the configuration of an image processing system embodying the present invention. The image processing system of the present invention comprises a digital camera 2 and an image processing server 3. The digital camera 2 and the image processing server 3 are connected by a network such as the Internet 4. The connection between the digital camera 2 and the Internet 4 and the image processing server 3 and the Internet 4 is performed by xDSL represented by ADSL, optical fiber,
High-speed communication networks such as cable TV, mobile phones and PIAF
They are connected by a wireless communication network such as S.

FIG. 2 is a block diagram showing the configuration of the digital camera 2. As is well known, a photographing optical system including a zoom lens 6 and a focus lens 7 is provided on the front surface of the digital camera 2. A diaphragm plate 8 for switching the diaphragm is provided between the zoom lens 6 and the focus lens 7.
However, a shutter blade 9 is arranged behind the focus lens 7.

The zoom lens 6 and the focus lens 7 are
The lenses are moved in the optical axis direction by lens driving mechanisms 12 and 13 each including a motor. The diaphragm plate 8 is moved by a diaphragm drive mechanism 14 including a motor in a direction orthogonal to the photographing optical axis. The shutter blade 9 is driven by a shutter drive mechanism 15 including a motor.

The lens drive mechanisms 12 and 13 and the diaphragm drive mechanism 14 are motor drivers 18 controlled by the CPU 17.
Driven by ~ 20. The shutter drive mechanism 15
When a timing signal is input from the timing generator 21, it is driven by the motor driver 22.

A lens barrier 25 which is manually opened and closed is provided in front of the photographing optical system. Lens barrier 25
The open / closed state of is detected by the lens barrier detection switch 26. The detection signal of the lens barrier detection switch 26 is input to the CPU 17 and used for determining whether shutter release is possible.

A CCD image sensor 28, which is well known as an image pickup device, is arranged behind the CPU 17. The subject light that has passed through the photographing optical system is imaged on the CCD image sensor 28 when the shutter blade 9 is opened. This CC
The D image sensor 28, like the shutter drive mechanism 15, captures an image when a timing signal is input from the timing generator 21.

The exterior of the digital camera 2 is provided with a shutter button that is operated during shooting. Inside the shutter button, a shutter switch 30 for detecting half-pressing and full-pressing of the shutter button is incorporated. The operation signal of the shutter switch 30 is input to the CPU 17.

The CPU 17 operates the AF circuit 32 and the AE / AWB circuit 33 in response to the half-press signal of the shutter switch 30. The AF circuit 32 measures the distance to the subject using a known light emitting element and light receiving element, and moves the focus lens 7 based on the measurement result to perform focusing. The AE circuit 32 measures the subject brightness and determines the aperture value, shutter speed, and the like. The AWB circuit is an auto white balance circuit, and automatically adjusts the white balance during shooting.

Further, the CPU 17 controls the shutter switch 3
In response to the full push signal of 0, the timing generator 21
To generate a timing signal. This timing signal is input to the shutter drive mechanism 15 and the CCD image sensor 28, and photographing is performed.

The CCD image sensor 28 generates an analog signal by photoelectric conversion. The analog signal is input to the image data generation unit 35. Image data generator 35
Is a correlated double sampling circuit (CDS), an auto gain controller (AGC), and an AD converter (AD
C) and. The CDS removes noise from the analog signal, and the AGC automatically adjusts the gain of the analog signal.
The ADC digitally converts the analog signal to generate 12-bit image data. Hereinafter, the image data immediately after AD conversion will be referred to as 12-bit CCD-RAW data.

The 12-bit CCD-RAW data created by the image data generator 35 is the image input controller 3
7 to the image memory 38. The image input controller 37 and the image memory 38 are connected to a data bus 39 connected to the CPU 17.

FIG. 3 is an explanatory diagram showing a storage state of 12-bit CCD-RAW data in the image memory 38. 12-bit CCD-RAW data uses one and a half bytes of the image memory 38 for one pixel. Since the remaining 4 bits are not used by other pixels, one pixel occupies 2 bytes of memory capacity.

12-bit C stored in the image memory 38
The CD-RAW data is read from the image memory 38 by the image input controller 37 and input to the image processing circuit 41 via the data bus 39. Image processing circuit 4
In No. 1, pre-processing including gamma correction, offset setting, gain setting, etc., and bit reduction processing is performed. In the bit reduction processing, 8-bit sampling processing is performed on 12-bit CCD-RAW data. This allows
8-bit CCD-RAW data is created.

The 8-bit CCD-RAW data is written in the image memory 38 by the image input controller 37. As shown in FIG. 4, since 8-bit CCD-RAW data uses a memory capacity of 1 byte for one pixel, the occupied amount of the image memory 38 is half that of 12-bit CCD-RAW data.

The 8-bit CCD-RAW data is subjected to simple YC processing in the image processing circuit 41 and converted into an NTSC composite signal by the video encoder 43. This composite signal is displayed on a liquid crystal display (LCD) 44 provided in the digital camera 2.

Taking an image with the CCD image sensor 28 and L
Switching between reproduction of a captured image on the CD 44 and a mode switching button provided on the exterior of the digital camera 2 is performed. A mode changeover switch 46 for generating an operation signal according to the operation of the mode changeover button is incorporated in the mode changeover button. The operation signal of the mode changeover switch 46 is input to the CPU 17 and used for timing of mode changeover.

A memory card 48 is used as a removable storage medium in the digital camera 2. A media controller 49 for accessing the memory card 48 to read and write data is provided in the digital camera 2 and is connected to the data bus 39.

Further, the digital camera 2 is provided with a communication circuit 51 for connecting to the Internet 4 using a high speed communication network. The 8-bit CCD-RAW data is transmitted from the communication circuit 51 to the image processing server 3 via the Internet 4.

As shown in FIG. 5, the image processing server 3 is
A data communication unit 54 that connects to the Internet using a high-speed communication network and a data storage 55 that stores the received 8-bit CCD-RAW data are provided. Further, the image quality correction unit 56, the YC processing unit, the data compression unit 60, which performs various image processes on the 8-bit CCD-RAW data,
The file conversion unit 62 is provided.

The image quality correction unit 56 includes a data storage 55.
The 8-bit CCD-RAW data is read out from the device and image quality adjustment such as brightness level correction and white balance correction is performed.

The YC processing unit 58 performs the image quality correction 8
YC processing is performed on the bit CCD-RAW data. As a result, the 8-bit CCD-RAW data is converted into YCbCr image data including luminance (Y) data and blue color difference (Cb) data and red color difference (Cr) data.

As shown in FIG. 6, in the YCbCr image data, 1 byte of Y data is formed for each pixel, and 1 byte of Cb data and Cr data is formed for every 2 pixels. Therefore, the data capacity becomes four times as large as that of the 8-bit CCD-RAW data. A conventional digital camera requires an image memory having a capacity capable of storing YCbCr image data, which causes an increase in cost of the digital camera. However, in the present invention, since the image processing server 3 performs the YC processing in which the data capacity increases, a small capacity image memory 38 of the digital camera 2 can be used.

The data compression unit 60 performs fixed length processing and compression processing on the YCbCr image data to create compressed image data. The data capacity of compressed image data is YCbC
It becomes about 1/10 of the data capacity of r image data.

The file conversion section 62 converts the compressed image data into image data in the jpeg format. The image data in the jpeg format is once recorded in the data storage 55 and is transmitted to the digital camera 2 by the data communication unit 54.

Next, the operation of the above embodiment will be described with reference to FIG.
And 8 will be described with reference to the flowcharts. When the power of the digital camera 2 is turned on and the mode switching button is set to the shooting mode, an operation signal is input to the CPU 17 from the mode switching switch 46.

The CPU 17 operates the shutter drive mechanism 15 to open the shutter blade 9. Next, the AF circuit 32 and the AE / AWB circuit 33 perform distance measurement and photometry for outputting a through image. The lens driving mechanism 13 operates according to the distance measurement result, and focusing is performed by moving the focus lens 7. Further, the diaphragm drive mechanism 14 operates to switch the diaphragm according to the photometric result.

The subject light that has passed through the photographing optical system is focused on the CCD image sensor 28, and the CCD image sensor 2
An analog signal is input from 8 to the image data generation unit 35. The image data generation unit 35 AD-converts the analog signal to create 12-bit CCD-RAW data. 12
The bit CCD-RAW data is stored in the image memory 38 by the image input controller 37.

The image processing circuit 41 reads 12-bit CCD-RAW data from the image memory 38. And
The 12-bit CCD-RAW data is subjected to pre-processing such as gamma correction, offset setting, gain setting, etc., and bit reduction processing to create 8-bit CCD-RAW data. In addition, 8-bit CCD-RAW data is a simple Y
C processing is performed and the result is input to the video encoder 43.
Then, it is converted into an NTSC signal and an image is displayed on the LCD 44. The through image display is performed on the LCD 44 by continuously performing the image capturing process at a constant cycle.

When framing is performed while checking the LCD 44 and the shutter button is half-pressed, a half-press signal is input to the CPU 17 from the shutter switch 30. CP
The U17 uses the AF circuit 32 and the AE / AWB circuit 33 to perform distance measurement and photometry for shooting, and performs focusing and aperture switching. It should be noted that when the shutter button is half-pressed, the through image output is restarted.

When the shutter button is fully pressed, a half-press signal is input from the shutter switch 30 to the CPU 17, and the photographing process is started. The CPU 17 once closes the shutter blade 9 and causes the timing generator 21 to generate a timing signal. In response to the timing signal input from the timing generator 21, the shutter blade 9 performs shutter release, and the CCD image sensor 28 captures a still image.

As shown in FIG. 1, the analog signal output from the CCD image sensor 28 is converted into 12-bit CCD-RAW data as in the case of outputting a through image,
Further, it is converted into 8-bit CCD-RAW data and stored in the image memory 38. In addition, the still image taken is
Simple YC processing of 8-bit CCD-RAW data and N
It is displayed on the LCD 44 by being encoded into the TSC signal.

The communication circuit 51 transmits the 8-bit CCD-RAW data read from the image memory 38 to the Internet 4 via a high speed communication network and inputs it to the image processing server 3. The image processing server 3 receives the received 8-bit CCD-R
The AW data is stored in the data storage 55.

The 8-bit CCD-RAW data stored in the data storage 55 is input to the image quality correction unit 56 and subjected to brightness level correction and white balance correction. The 8-bit CCD-RAW data subjected to the image quality correction is input to the YC processing unit 58 and converted into YCbCr image data. The YCbCr image data has a data capacity four times that of the 8-bit CCD-RAW data, but there is no problem because the data storage 55 of the image processing server 3 has a large storage capacity.

The YCbCr image data is stored in the data compression unit 6
When it is input to 0, fixed length processing and compression processing are performed. Further, the file conversion unit 62 converts the image data into jpeg format which is a standard file format in a digital camera.

The jpeg image data is temporarily stored in the data storage 55. The image processing server 3 sends a transmission request signal to the digital camera 2. When the digital camera 2 is ready for reception, the digital camera 2 transmits a reception request signal to the image processing server 3.

When the image processing server 3 receives the reception request signal from the digital camera 2, the data communication unit 54 transmits the jpeg image data to the digital camera 2. j
Since the peg image data has a data capacity of about 1/3 of the 8-bit CCD-RAW data, the image processing server 3
The transmission from the digital camera 2 to the digital camera 2 is completed in a short time.

The digital camera 2 receives the jpeg image data from the image processing server 3 in the communication circuit 51,
It is stored in the image memory 38. Then, the jpeg image data is stored in the memory card 48 via the media controller 49. After that, the through image output is started again, and the next shooting becomes possible.

A high-speed communication network is used for data communication between the digital camera 2 and the image processing server 3, and 8-bit CCD-RAW data having a relatively small capacity and jpeg image data having a small capacity are used. Since the image data is transmitted, the image data transmission is completed in a short time. Further, since the image processing server 3 uses a high performance CPU,
Conversion from 8-bit CCD-RAW data to jpeg image data is completed in an instant. As a result, it is possible to obtain a processing speed comparable to that of the conventional digital camera that has internally performed all image processing.

Further, by updating the image processing program of the image processing server, it is possible to always obtain optimally processed image data without replacing the digital camera.

In the above embodiment, after the 8-bit CCD-RAW data is transmitted from the digital camera 2 to the image processing server 3, the digital camera 2 can take the next image until the jpeg image data is received. There wasn't. However, it is possible to enable the next photographing immediately after transmitting the 8-bit CCD-RAW data to the server.

In order to enable photographing even during processing in the image processing server, an image memory having a capacity capable of storing the jpeg image data received from the server and 12-bit CCD-RAW data for another screen is provided. It suffices to use it so that through image output and data reception can be processed in parallel.

For example, as shown in the flow chart of FIG. 9, when there is no free space in the image memory, the jpeg image data is received after waiting for the transmission request signal from the image processing server, as in the above embodiment. Store in memory card.

If the image memory has a free space, the process shifts to the process AA 'shown in FIG. This process A
At −A ′, the process shifts to through image output until the transmission request is received from the image processing server 3, and the next shooting can be performed. It should be noted that, in order not to miss the transmission request from the image processing server, the processing AA ′ may be performed during the output of the through image.

In the above embodiment, only basic image processing is performed in the image processing server, but the shading correction and distortion correction which are difficult to process in the digital camera are utilized by utilizing the processing capability of the image processing server. And so on. The image processing server can also perform image composition with characters, frames, and the like.

The image data is transmitted to the image processing server every time one image is taken. However, when a large number of images are taken continuously by using the continuous shooting function or the like, a plurality of images are taken. The image data may be collectively transmitted to the image processing server. Also, in the case of a digital camera capable of shooting moving images, moving image data may also be transmitted to the image processing server for image processing, data encoding, and the like.

[0055]

As described above, since the image processing which is conventionally performed in the digital camera is performed by the image processing server, it is possible to reduce the load on the image processing in the digital camera. The cost of the camera can be reduced.

Further, since the high speed communication network is used and the image data of which the bit is reduced in the digital camera is transmitted to the server, the internal processing of all is performed in combination with the high speed processing capability of the image processing server. It is possible to obtain a processing speed comparable to that of a conventional digital camera.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a configuration of an image processing system of the present invention.

FIG. 2 is a block diagram showing a configuration of a digital camera.

FIG. 3 is an explanatory diagram showing a storage state of 12-bit CCD-RAW data in an image memory.

FIG. 4 is an explanatory diagram showing a storage state of 8-bit CCD-RAW data in an image memory.

FIG. 5 is a block diagram showing a configuration of an image processing server.

FIG. 6 is an explanatory diagram showing a storage state of YCbCr image data in an image memory.

FIG. 7 is a flowchart of a digital camera.

FIG. 8 is a flowchart of an image processing server.

FIG. 9 is a flowchart of a digital camera that enables continuous shooting.

FIG. 10 is a flowchart of a process AA ′ of the flowchart shown in FIG.

[Explanation of symbols]

2 digital camera 3 Image processing server 17 CPU 28 CCD image sensor 38 image memory 41 Image processing circuit 51 communication circuit 54 Data Communication Department 56 Image quality correction section 58 YC processing unit 60 data compression unit 62 File converter

Continued front page    F-term (reference) 5C052 GA02 GA08 GB06 GC05 GE08                 5C053 FA08 GA11 GB06 GB36 KA04                       KA24 LA02 LA14                 5C055 AA06 BA03 EA02 EA04 HA18                 5C062 AA01 AA16 AA29 AB38 AC25                       AC34 AE01 AF14 BA02

Claims (3)

[Claims] 1. An image sensor which outputs an analog signal in response to a photographing operation, an AD converter which digitally converts an analog signal output from the image sensor to create image data, and an image data read out from an image memory. A low-bit image data received from the digital camera, and a digital camera equipped with a low-bit means for performing low-bit image data by performing a bit conversion process and a communication means for transmitting and receiving data to and from an external device. , An YC process, a fixed length process, and a compression process to create compressed image data, and an image processing server that transmits the compressed image data to a digital camera. 2. The image processing system according to claim 1, wherein a captured image is displayed on the image display means of the digital camera by using the low bit image data. 3. The image processing system according to claim 1, wherein the image processing server performs image quality correction processing on the low bit image data.