KR101589490B1 - Apparatus and method for compressing/decompressing image in digital image processing device - Google Patents

Abstract

The present invention relates to an apparatus and method for compressing and storing an image in a digital image processor and decompressing and reproducing the stored image. An image compression and decompression apparatus is a digital image processor, comprising: a first compression and decompression unit compressing a photographed image into a thumbnail image and a main image; A second compression and decompression unit compressing the photographed image into a screen nail image; And a controller for synthesizing images compressed by the first compression / decompression unit and the second compression / decompression unit to generate an image file.

Main video and thumbnail video, JPEG codec, screen nail video, H.264 codec

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image compression and decompression apparatus and a digital image processing apparatus,

The present invention relates to an apparatus and method for compressing and storing an image in a digital image processor and decompressing and reproducing the stored image.

In order to display images at high speed as the resolution of a digital image processor increases, an image reduced to a smaller size compared to the original image has been further processed and used. That is, it is possible to process at a high speed by utilizing the small size of the screen nail image during display and browsing. In addition, in order to reduce the storage capacity of the screen nail image, it is generally compressed and stored as JPEG.

Conventionally, an image captured only by an LCD window of a digital image processor has been reproduced. However, as digital TV is becoming common, there are many cases in which a captured image is viewed or browsed by connecting to a TV. For this purpose, the screen nail image should be enlarged and stored in HD size so that it can be processed in digital TV without loss of image quality. However, after additionally storing the screen nail image of the HD-level image size, it is burdensome for the storage capacity to be displayed later.

The technical problem to be solved by the present invention is to secure the storage space of the screen nail image by processing the main image and the thumbnail image as JPEG and the screen nail image as H.264 when generating the image file, And to provide an apparatus and method for compressing and decompressing an image in a digital image processor capable of being displayed on a digital TV.

According to an aspect of the present invention, there is provided an image compression and decompression apparatus comprising: a first compression and decompression unit for compressing a photographed image into a thumbnail image and a main image; A second compression and decompression unit compressing the photographed image into a screen nail image; And a controller for synthesizing images compressed by the first compression / decompression unit and the second compression / decompression unit to generate an image file.

In the present invention, the controller may generate an image file composed of a thumbnail image and a main image compressed by the first compression / decompression unit and a screen nail image compressed by the second compression / decompression unit.

In the present invention, the controller may store the screen nail image in a MakerNote data area including shooting information of the image file.

In the present invention, the thumbnail image and the main image compressed from the generated image file are released and reproduced by the first compression and decompression unit, and a compressed screen nail image is compressed from the generated image file by the second compression and decompression Can be released and reproduced.

In the present invention, the first compression and decompression unit may be a JPEG codec, and the second compression and decompression unit may be an H.264 codec.

According to an aspect of the present invention, there is provided an image compressing and decompressing method including: (a) generating a thumbnail image and a main image by first compressing a photographed image; (b) performing a second compression process on the photographed image to generate a screen nail image; And (c) synthesizing the first and second compressed images to generate an image file.

In the present invention, in step (c), an image file composed of the thumbnail image subjected to the first compression processing and the screen image of the main image and the second compression-processed screen nail image may be generated.

In the present invention, in the step (c), the screen nail image may be stored in a MakerNote data area including shooting information of the image file.

In the present invention, the first compression process may be performed by the JPEG codec, and the second compression process may be performed by the H.264 codec.

In the present invention, the compressed thumbnail image and the main image from the generated image file are released by the JPEG codec, and the compressed screen nail image is released from the generated image file by the H.264 codec have.

As described above, according to the present invention, when the image file is generated, the main image and the thumbnail image are processed as JPEG, and the screen nail image is processed as H.264, thereby securing the storage space of the screen nail image, Create displayable effects on your TV.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts may be omitted so as not to disturb the gist of the present invention.

It is also to be understood that the terms and words used in the following description and claims are not to be construed in a limiting sense and that they are used in a generic and descriptive sense only and not for purposes of the present invention, Should be interpreted as a concept.

1 is a block diagram showing the configuration of an image compression and decompression apparatus in a digital image processor according to the present invention. 1, a digital image processor according to the present invention includes a zoom lens 102, a diaphragm 104, a focus lens 106, driving devices 102a, 104a, and 106a, a complementary metal oxide semiconductor (CMOS) A correlated double sampling (CDS) amplifier 110, an A / D converter 112, an image input controller 114, an image signal processing unit 116, a compression processing unit 120, an OSD (on) a liquid crystal display (LCD) drive 122, an LCD 124, a timing generator 126, a central processing unit (CPU) 128, an operation unit 132, a shutter button 133, A memory 134, a video random access memory (VRAM) 136, a media controller 138, a recording medium 140, motor drivers 142a, 142b and 142c, and a flash 144. [

The zoom lens 102 is a lens which is moved back and forth in the direction of the optical axis by the driving device 102a and changes continuously with the focal length, and changes the size of the subject and photographs it. The diaphragm 104 adjusts the amount of light entering the CMOS device 108 by the driving device 104a when capturing an image. The focus lens 106 adjusts the focus of the subject by moving back and forth in the direction of the optical axis by the driving device 106a.

In this embodiment, only one zoom lens 102 and one focus lens 106 are shown. The number of the zoom lenses 102 may be two or more, and the number of the focus lenses 106 may be two or more.

The CMOS device 108 is an element for converting the light incident from the zoom lens 102, the diaphragm 104, and the focus lens 106 into an electric signal. In this embodiment, the time for extracting the electric signal is controlled by controlling the incident light by the electronic shutter. However, the time for extracting the electric signal by controlling the incident light by using the mechanical shutter may be adjusted. In this embodiment, the image pickup section is constituted by the zoom lens 102, diaphragm 104, focus lens 106, and CDS amplifier 110. The set of image pickup units is not limited to this, and may be a configuration not including the zoom lens 102 or the diaphragm 104.

In this embodiment, a CMOS device 108 is used, and preferably a high-speed CMOS image sensor. Here, the digital image processor 100 can perform 60 consecutive shots per second through the high-speed CMOS image sensor. The CDS amplifier 110 is a circuit in which a CDS circuit and an amplifier for amplifying an electric signal after noise removal are integrated is a kind of sampling circuit for eliminating the noise of the electric signal outputted from the CMOS element 108. In the present embodiment, the digital image processor 100 is constituted by using a circuit in which the CDS circuit and the amplifier are integrated. However, the CDS circuit and the amplifier may be constituted by separate circuits.

The A / D converter 112 converts the electric signal generated in the CMOS device 108 into a digital signal to generate RAW data of the image.

The image input controller 114 performs control for inputting the RAW data of the image generated by the A / D converter 112 to the memory 134.

The video signal processing unit 116 performs gain correction and white balance adjustment of the light amount with respect to the electric signal output from the CMOS device 108. [ The image signal processing unit 116 acquires exposure data of the photographed image. The exposure data includes an in-focus evaluation value (AF evaluation value) and an AE (auto exposure) evaluation value. The calculation of the in-focus evaluation value or the AE evaluation value is performed.

The compression and decompression processing unit 120 performs compression processing for compressing the image processed in the image signal processing unit 116 into image data of an appropriate format. The compression format of the image may be reversible or irreversible.

FIG. 2 is a schematic block diagram of the compression / decompression processing unit 120 according to the present embodiment, and includes a JPEG codec 120-1 and an H.264 codec 120-2.

A thumbnail image and a screen nail image are acquired by a photographing operation of the digital image processor 100. The JPEG CODEC 120-1 compresses and releases the main image and the thumbnail image, The .264 codec 120-2 compresses and decompresses the screen nail image.

Since the main profile / high profile of the H.264 codec 120-2 is continuously supported in the local digital image processor 100 to generate a high quality image, the difference in compression efficiency from the JPEG codec 102-1 Lt; / RTI > The H.264 codec 102-2 is an approved open standard that supports the most efficient image compression and decompression technology at present. The H.264 codec 120-2 has an image quality comparable to that of the JPEG codec 120-1 It can reduce digital image file size by more than 50% without any damage.

Depending on the profile, the H.264 codec 120-2 may use different frame types such as I-frame, P-frame and B-frame depending on the profile, without reference to other images for screen nail image compression and decompression An I-frame, i.e., an intra frame, which is a stand-alone frame type that can be independently decoded, is used.

The OSD 121 displays a setting screen of the digital image processor 100 on the LCD 124. [ The LCD 124 displays a live view image before performing the photographing operation, various setting screens of the digital image processor 100, and displays the photographed image. The display of the image data or various information of the digital image processor 100 on the LDC 124 is performed via the LCD drive 122. [

The timing generator 126 inputs a timing signal to the CMOS device 108. The shutter speed is determined by the timing signal from the timing generator 126. That is, the driving of the CMOS device 108 is controlled by the timing signal from the timing generator 126, and the video light from the subject is incident within the time that the CMOS device 108 is driven, A signal is generated.

The CPU 128 executes a command of the signal system to the CMOS element 108 or the CDS amplifier 110 or executes an instruction of the operation system with respect to the operation of the operation unit 132. [ In this embodiment, only one CPU 128 is included, but instructions of the signal system and instructions of the operating system may be executed by separate CPUs. In this embodiment, the CPU 128 generates an image file using the main image, the thumbnail image, and the screen nail image compressed by the compression / decompression processing unit 120, and controls the generated image file to be reproduced. This will be described below.

The operation unit 132 is provided with members for performing operations of the digital image processor 100 and performing various settings at the time of shooting. A member disposed in the operation section 132 is provided with a power button, a cross key for selecting a photographing mode or a photographing drive mode, and a soft key effect setting button, and a selection button. The shutter button 133 is for performing a photographing operation. The shutter button 133 is used to focus the subject in the half-depressed state and photograph the subject in the fully depressed state.

The memory 134 is an example of a video storage unit, and temporarily stores the captured video or the video compressed by the decompression processing unit 120. The memory 134 has a storage capacity sufficient to store a plurality of images. The reading and writing of the image into the memory 134 is controlled by the image input controller 114.

The VRAM 136 maintains the contents to be displayed on the LCD 124. The resolution and the maximum number of colors of the LCD 124 depend on the capacity of the VRAM 136. [

The recording medium 140 is an example of a video recording unit, and records a photographed video. The input / output to / from the recording medium 140 is controlled by the media controller 138. As the recording medium 140, a memory card which is a card-type storage device for recording data in a flash memory can be used.

The motor drivers 142a, 142b and 142c control the driving devices 102a, 104a, and 106a that operate the zoom lens 102, the diaphragm 104, and the focus lens 106. [ The zoom lens 102, the diaphragm 104 and the focus lens 106 are operated via the motor drivers 142a, 142b and 142c to adjust the size of the subject, the amount of light, and the focus.

The flash 144 is for illuminating the subject brightly at the time of shooting at nighttime outdoors or in a dark place. A light emission instruction is inputted from the CPU 128 to the flash 144 and the flash 144 is emitted in response to the light emission instruction from the CPU 128 so that the flash 144 The subject shines brightly.

FIG. 3 is a schematic block diagram of the CPU 128 shown in FIG. 1, which controls the overall operation of the digital image processor 100. In this embodiment, the CPU 128 generates an image file using the main image, the thumbnail image, and the screen nail image compressed by the compression / decompression processing unit 120, and controls the reproduced image file to be reproduced. To this end, the CPU 128 includes a JPEG image generation unit 128-1, an H.264 image generation unit 128-2, and an image file generation unit 128-3.

The JPEG image generation unit 128-1 receives the compressed main image and thumbnail image from the JPEG codec 120-1 and generates an image for composing the image file.

The H.264 image generating unit 128-2 receives the compressed screen nail image from the H.264 codec 120-2 and generates an image for composing the image file.

The image file generation unit 128-3 generates an image file including a compressed main image, a thumbnail image, and a screen nail image generated by the JPEG image generation unit 128-1 and the H.264 image generation unit 128-2. . In this embodiment, the image file generation unit 128-3 stores the screen nail image generated by the H.264 image generation unit 128-2 in the MakerNote data area including the shooting information among the image files.

FIG. 4A shows a general JPEG file structure. A typical JPEG image file has a structure of [Header] [Thumbnail] [MainImage] [ScreenNail].

A header is additional information embedded in a JPEG file as data that stores various types of information used in the digital image processor 100. The header can record various additional information such as the shooting date and time, the shutter speed, the aperture value, whether to use the flash, the ISO setting value, and the zoom magnification. Such information is basically not displayed on the image, and the captured image is provided as additional information when viewed in the image viewer. The thumbnail image can be conveniently made smaller than the main image (160 × 120) in order to facilitate the reproduction of the photographed image, and the main image retrieval can be conveniently performed using the thumbnail image, The retrieval time can be shortened. The screennail image is an image compressed in accordance with the size of the visible area of the LCD 124 (for example, 640 x 480) separately from the thumbnail image. In the image reproduction mode, the screen nail image is restored and displayed on the LCD 124. [

FIG. 4B shows a structure of an image file generated according to the present invention, and has a structure of [Header] [Thumbnail] [MainImage].

The header includes a MakerNote data area including shooting information, and stores the screen nail image generated by the H.264 image generator 128-2 in the MakerNote data area. In this embodiment, since the H.264 codec 120-2 can support the VGA class, the SVGA class, the full HD class beyond 720P or 1080P, the screen nail generated by the H.264 video generator 128-2 The image can be enlarged to HD size and can be played back on digital TV.

Then, at the time of image reproduction, the CPU 128 releases the compressed thumbnail image and the main image from the generated image file in the JPEG CODEC 120-1 and reproduces the compressed thumbnail image and the main image, and outputs the compressed screen nail image from the generated image file to the MakerNote And released from the H.264 codec 120-2 to be reproduced.

Next, an image compression and decompression method in the digital image processor according to the present invention will be described with reference to FIGS. 5 and 6. FIG.

5, an image is compressed using the digital image processor 100, and the JPEG image generator 128-1 generates a JPEG image from the JPEG codec 120-1, The main image and the thumbnail image are generated from the compressed image in operation 520. The H.264 image generation unit 128-2 generates a screen nail image from the H.264 compressed image from the H.264 codec 120-2 (Step 530).

Since the main profile / high profile of the H.264 codec 120-2 is continuously supported in the local digital image processor 100 to generate a high quality image, the difference in compression efficiency from the JPEG codec 102-1 Lt; / RTI > The H.264 codec 102-2 is an approved open standard that supports the most efficient image compression and decompression technology at present. The H.264 codec 120-2 has an image quality comparable to that of the JPEG codec 120-1 It can reduce digital image file size by more than 50% without any damage.

Depending on the profile, the H.264 codec 120-2 may use different frame types such as I-frame, P-frame and B-frame depending on the profile, without reference to other images for screen nail image compression and decompression An I-frame, i.e., an intra frame, which is a stand-alone frame type that can be independently decoded, is used.

In operation 540, the image file generation unit 128-3 generates and stores an image file using the compressed JPEG main image and the thumbnail image and the compressed H.264 screen nail image. At this time, the image file generation unit 128-3 stores the screen nail image generated by the H.264 image generation unit 128-2 in the MakerNote data area including the shooting information among the image files.

FIG. 4A shows a general JPEG file structure. A typical JPEG image file has a structure of [Header] [Thumbnail] [MainImage] [ScreenNail].

A header is additional information embedded in a JPEG file as data that stores various types of information used in the digital image processor 100. A thumbnail image is a smaller and simpler image (eg, 160 × 120) than the main image to make it easier to play back the captured image. The thumbnail image makes it easier to search the main image, The retrieval time can be shortened. The screen nail image is compressed according to the size of the visible area of the LCD 124 (for example, 640 x 480) separately from the thumbnail image. In the image reproduction mode, the screen nail image is restored and displayed on the LCD 124. [

FIG. 4B shows a structure of an image file generated according to the present invention, and has a structure of [Header] [Thumbnail] [MainImage].

The header includes a MakerNote data area including shooting information, and stores the screen nail image generated by the H.264 image generator 128-2 in the MakerNote data area. In this embodiment, since the H.264 codec 120-2 can support the VGA class, the SVGA class, the full HD class beyond 720P or 1080P, the screen nail generated by the H.264 video generator 128-2 The image can be enlarged to HD size and can be played back on digital TV.

6, when the digital image processor 100 enters the image reproduction mode (step 610), the CPU 128 determines whether to reproduce the screen nail image by the user input signal (Step 620). When the screen nail image is reproduced, the H.264 codec 120-2 is instructed to read the H.264 compressed screen nail image from the MakerNote of the image file to be reproduced, (Step 630).

In operation 640, the CPU 128 determines whether to reproduce the main image or the thumbnail image according to the user input signal. When the main image or the thumbnail image is reproduced, the CPU 128 instructs the JPEG codec 120-1 to reproduce the image file A JPEG compressed main image or a thumbnail image is read out and JPEG decompressed and reproduced (operation 650).

1 is a block diagram showing the configuration of an image compression and decompression apparatus in a digital image processor according to the present invention.

2 is a schematic block diagram of the compression and decompression processing unit 120 shown in FIG.

3 is a schematic block diagram of the CPU 128 shown in FIG.

4 is a diagram showing a conventional image file structure and an image file structure of the present invention.

5 is a flowchart illustrating an operation of an image compression method in a digital image processor according to the present invention.

6 is a flowchart illustrating an operation of an image decompression method in a digital image processor according to the present invention.

Claims (10)

As a digital image processor, A first compression and decompression unit compressing the photographed image into a thumbnail image and a main image; A second compression and decompression unit compressing the photographed image into a screen nail image; And And a controller for synthesizing images compressed by the first compression / decompression unit and the second compression / decompression unit to generate an image file, The control unit And generates an image file composed of a thumbnail image and a main image compressed by the first compression and decompression unit and a screen nail image compressed by the second compression and decompression unit. delete The apparatus of claim 1, wherein the control unit And stores the screen nail image in a MakerNote data area including shooting information of the image file. The method of claim 3, The second compression and decompression unit releases the compressed thumbnail image and the main image from the generated image file in the first compression and decompression unit and reproduces the compressed thumbnail image and the main image from the generated image file, The image compression and decompression device. 5. The apparatus of claim 4, wherein the first compression and decompression unit is a JPEG codec, and the second compression and decompression unit is an H.264 codec. As an operation method of a digital image processor, (a) generating a thumbnail image and a main image by first compressing the photographed image; (b) performing a second compression process on the photographed image to generate a screen nail image; And (c) synthesizing the first and second compressed processed images to generate an image file, In the step (c) And generating an image file composed of the thumbnail image subjected to the first compression processing and the main image and the screen-nail image subjected to the second compression processing. delete 7. The method of claim 6, wherein in step (c) Wherein the screen nail image is stored in a MakerNote data area including shooting information of the image file. The method of claim 8, wherein the first compression process is performed by a JPEG codec, and the second compression process is performed by an H.264 codec. 10. The method of claim 9, And decompressing the compressed thumbnail image and the main image from the generated image file by using the JPEG codec and playing back the second thumbnail image and the main image from the generated image file and releasing the compressed second screen nail image to the H.264 codec, How to compress and decompress images.

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