KR20100055942A - Apparatus and method for compressing/decompressing image in digital image processing device - Google Patents

Abstract

PURPOSE: An apparatus and a method for compressing/decompressing an image in digital image processing device are provided to display a screen nail image by processing the image of a screen nail image through H.264 and processing a main image and a thumbnail image through JPEG. CONSTITUTION: An image is picked up through a digital image processor(510). A JPEG(Joint Photographic Expert Group) image generator creates a main image and a thumbnail image from a JPEG image(520). The JPEG image is compacted from a JPEG codec. An H.264 image generator creates a screen nail image from the H.264 image(530). The H.264 image is compacted from the H.264 codec.

Description

Apparatus and method for compressing / decompressing image in digital image processing device}

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

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

Conventionally, images captured only by the LCD window of the digital image processor have been reproduced. However, as digital TVs are becoming more common, many users connect to a TV and watch or browse the images. To do this, the screen thumbnail image must be enlarged and stored in HD size so that it can be processed in digital TV without loss of quality. However, the additional storage capacity of the screen-size image of the HD size is a burden on the storage capacity for later display.

The technical problem to be solved by the present invention is to process the main image and thumbnail image in JPEG and the screen thumbnail image in H.264 when generating the image file, to secure the storage space of the screen thumbnail image and to display the screen thumbnail image The present invention provides an apparatus and method for compressing / decompressing an image in a digital image processor that can be displayed on a digital TV.

An image compression / decompression apparatus for solving the technical problem to be achieved by the present invention is a digital image processor, comprising: a first compression / decompression unit for compressing a captured image into a thumbnail image and a main image; A second compression / decompression unit configured to compress the captured image into a screen nail image; And a controller configured to synthesize an image compressed by the first compression / decompression unit and the second compression / decompression unit to generate an image file.

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

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

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

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

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

In the present invention, in the step (c), it is possible to generate an image file consisting of the first compressed thumbnail image and main image and the second compressed screen thumbnail image.

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

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

In the present invention, a thumbnail image and a main image compressed from the generated image file can be released by the JPEG codec and played back, and a compressed screen thumbnail image from the generated image file can be released 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 in JPEG, and the screen thumbnail image is processed in H.264, thereby securing the storage space of the screen thumbnail image and digitally converting the screen thumbnail image. Create a displayable effect on a TV.

Hereinafter, exemplary 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 are described, and descriptions of other parts may be omitted so as not to distract from the gist of the present invention.

In addition, terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and meanings consistent with the technical spirit of the present invention to best express the present invention. It should be interpreted as a concept.

1 is a block diagram showing the configuration of an image compression / decompression apparatus in a digital image processor according to the present invention. As shown in FIG. 1, the digital image processor according to the present invention includes a zoom lens 102, an aperture 104, a focus lens 106, driving devices 102a, 104a, 106a, and a complementary metal oxide semiconductor (CMOS) device 108. ), An integrated CDS amplifier 110, an A / D converter 112, an image input controller 114, an image signal processor 116, a compression processor 120, an OSD (on) screen display (121), liquid crystal display (LCD) drive 122, LCD 124, timing generator 126, central processing unit (CPU) 128, control panel 132, 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, 142c, and a flash 144.

The zoom lens 102 is a lens which is moved back and forth in the optical axis direction by the driving device 102a and changes continuously with the focal length. When the aperture 104 captures an image, the aperture 104 adjusts the amount of light entering the CMOS element 108 by the driving device 104a. The focus lens 106 adjusts the focus of the subject by moving back and forth in the optical axis direction by the driving unit 106a.

In the present 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 element 108 is an element for converting light incident from the zoom lens 102, the aperture 104, and the focus lens 106 into an electrical signal. In this embodiment, the time for extracting the electric signal by controlling the incident light by the electronic shutter is adjusted. The time for extracting the electric signal by controlling the incident light by using the mechanical shutter may be adjusted. In the present exemplary embodiment, the image capturing unit includes a zoom lens 102, an aperture 104, a focus lens 106, and a CDS amplifier 110. Moreover, the set of imaging sections is not limited to this, The structure which does not include the zoom lens 102 and the diaphragm 104 may be sufficient.

In this embodiment, the CMOS element 108 is used, and is preferably a high speed CMOS image sensor. Here, the digital image processor 100 may shoot 60 images per second through the high speed CMOS image sensor. The CDS amplifier 110 is a circuit in which a CDS circuit and a amplifier for amplifying an electrical signal after removing the noise are one type of a sampling circuit for removing noise of the electrical signal output from the CMOS element 108. In the present embodiment, the digital image processor 100 is configured by using a circuit in which the CDS circuit and the amplifier are integrated, but the CDS circuit and the amplifier may be configured as separate circuits.

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

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

The image signal processing unit 116 performs gain correction or light balance adjustment on the amount of light with respect to the electric signal output from the CMOS element 108. The image signal processing unit 116 acquires exposure data of the captured image, and the exposure data includes a focal point evaluation value (AF evaluation value) or AE (auto exposure) evaluation value. The image signal processing unit 116 Calculate the in-focus evaluation value or AE evaluation value in.

The compression / decompression processing unit 120 performs a compression process of compressing the image processed by the image signal processing unit 116 into image data of an appropriate format. The compressed format of the image may be a reversible format or an irreversible format.

2 shows 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.

The digital image processor 100 acquires a main image, a thumbnail image, and a screen thumbnail image by the capturing operation of the digital image processor 100. The JPEG codec 120-1 compresses / decompresses the main image and the thumbnail image. The .264 codec 120-2 compresses / decompresses the screen thumbnail image.

As 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 JPEG codec 102-1 differs in compression efficiency. Will be gone. The H.264 codec 102-2 is an open, approved standard that currently supports the most efficient video compression / decompression technology. The H.264 codec 120-2 is capable of providing a higher quality image than the JPEG codec 120-1. Digital image file size can be reduced by more than 50% without damage.

According to 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 referring to other images for screennail image compression / decompression. An I-frame, that is, an independent frame form that can be independently decoded, is used, namely an intra frame.

The OSD 121 performs a function of displaying the setting screen of the digital image processor 100 on the LCD 124. The LCD 124 displays a live view image before performing a photographing operation, various setting screens of the digital image processor 100, a display of photographed images, and the like. 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. In other words, the driving of the CMOS element 108 is controlled by the timing signal from the timing generator 126, and the image light from the subject is incident within the time period when the CMOS element 108 is driven, thereby providing the basis of the image data. The signal is generated.

The CPU 128 executes a signal system command to the CMOS element 108, the CDS amplifier 110, or the like, or performs a command of the operation system for the operation of the operation unit 132. In the present embodiment, only one CPU 128 is included, but the command of the signal system and the command of the operation system may be performed by separate CPUs. In the present embodiment, the CPU 128 generates an image file using the main image, thumbnail image, and screen thumbnail image compressed by the compression / decompression processing unit 120 and controls the generated image file to be played back. It will be described below.

The operation unit 132 is disposed with a member for performing an operation of the digital image processor 100 or for performing various settings when photographing. On the member disposed on the operation unit 132, a power button, a cross key for selecting the photographing mode or the photographing drive mode, and setting the soft focus effect, and the like are arranged. The shutter button 133 is used to perform a photographing operation. The shutter button 133 combines the subject in a half-pressed state and photographs the subject in a fully-pressed state.

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

The VRAM 136 retains the contents displayed on the LCD 124, and 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 an image recording unit and records a photographed image. Input / output to the recording medium 140 is controlled by the media controller 138. The recording medium 140 may be a memory card that is a card-type storage device for recording data in a flash memory.

The motor drivers 142a, 142b, and 142c perform control of the driving devices 102a, 104a, 106a for operating the zoom lens 102, the aperture 104, and the focus lens 106. By operating the zoom lens 102, the aperture 104, and the focus lens 106 via the motor drivers 142a, 142b, and 142c, the size of the subject, the amount of light, and the focus are adjusted.

The flash 144 is for illuminating the subject brightly when shooting outdoors at night or in a dark place. When performing flash photography, a light emitting command is input from the CPU 128 to the flash 144, and the flash 144 emits light according to the light emitting command from the CPU 128, so that the flash 144 emits light. The subject is shining brightly.

FIG. 3 is a schematic block diagram of the CPU 128 shown in FIG. 1 and controls the overall operation of the digital image processor 100. In the present embodiment, the CPU 128 generates an image file using the main image, the thumbnail image, and the screen thumbnail image compressed by the compression / decompression processor 120, and controls the generated image file to be played back. The CPU 128 includes a JPEG image generator 128-1, an H.264 image generator 128-2, and an image file generator 128-3.

The JPEG image generating unit 128-1 receives the main image and the thumbnail image compressed from the JPEG codec 120-1 to generate an image for constructing an image file.

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

The image file generator 128-3 is an image file including the compressed main image, thumbnail image, and screen thumbnail image generated by the JPEG image generator 128-1 and the H.264 image generator 128-2. Create In the present embodiment, the image file generation unit 128-3 stores the screen thumbnail image generated by the H.264 image generation unit 128-2 in the MakerNote data area including shooting information in the image file.

A general JPEG file structure is shown in FIG. 4A, which has a structure of [Header] [Thumbnail] [MainImage] [ScreenNail].

A header is data that stores various types of information used in the digital image processor 100 and is additional information inserted into a JPEG file. It is possible to record various additional information such as shooting date, shutter speed, aperture value, flash use, ISO setting value, zoom magnification, etc. in the header. Such information does not appear in the image by default, but is provided as additional information when the photographed image is viewed with the image viewer. Thumbnail image is a smaller and more concise image (e.g. 160 × 120) than main image to make playback of the captured image easier. Thumbnail image makes it easier to search the recorded main image. Search time can be shortened. The screen thumbnail image is an image compressed to fit the size of the visible area of the LCD 124 (for example, 640 × 480) separately from the thumbnail image. In the image playback mode, the screen thumbnail image is restored and displayed on the LCD 124.

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

The MakerNote data area including the shooting information exists in the header. The screennail image generated by the H.264 image generator 128-2 is stored in the MakerNote data area. In the present embodiment, since the H.264 codec 120-2 can support VGA, SVGA, 720P, or 1080P up to Full HD level, the screen thumbnail generated by the H.264 image generator 128-2 is generated. The video is enlarged to HD size and can be played on digital TV.

Subsequently, at the time of image reproduction, the CPU 128 releases and reproduces the compressed thumbnail image and the main image from the generated image file by the JPEG codec 120-1, and displays the compressed screen thumbnail image from the generated image file. Are read from the H.264 codec 120-2 and played back.

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

First, the image compression method will be described with reference to FIG. 5. When an image is captured using the digital image processor 100 (510), the JPEG image generation unit 128-1 performs JPEG from the JPEG codec 120-1. The main image and the thumbnail image are generated from the compressed image (step 520), and the H.264 image generator 128-2 generates the screen thumbnail image from the H.264 compressed image from the H.264 codec 120-2. Create (step 530).

As 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 JPEG codec 102-1 differs in compression efficiency. Will be gone. The H.264 codec 102-2 is an open, approved standard that currently supports the most efficient video compression / decompression technology. The H.264 codec 120-2 is capable of providing a higher quality image than the JPEG codec 120-1. Digital image file size can be reduced by more than 50% without damage.

According to 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 referring to other images for screennail image compression / decompression. An I-frame, that is, an independent frame form that can be independently decoded, is used, namely an intra frame.

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

A general JPEG file structure is shown in FIG. 4A, which has a structure of [Header] [Thumbnail] [MainImage] [ScreenNail].

A header is data that stores various types of information used in the digital image processor 100 and is additional information inserted into a JPEG file. Thumbnail image is a smaller and more concise image (e.g. 160 × 120) than main image to make playback of the captured image easier. Thumbnail image makes it easier to search the recorded main image. Search time can be shortened. The screen thumbnail image is an image compressed to fit the size (eg, 640 × 480) of the visible area of the LCD 124 separately from the thumbnail image. In the image playback mode, the screen thumbnail image is restored and displayed on the LCD 124.

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

The MakerNote data area including the shooting information exists in the header. The screennail image generated by the H.264 image generator 128-2 is stored in the MakerNote data area. In the present embodiment, since the H.264 codec 120-2 can support VGA, SVGA, 720P, or 1080P up to Full HD level, the screen thumbnail generated by the H.264 image generator 128-2 is generated. The video is enlarged to HD size and can be played on digital TV.

Next, referring to FIG. 6, the decompression method of the image will be described. When the digital image processor 100 enters the image playback mode (step 610), the CPU 128 may determine whether to reproduce the screen thumbnail image by the user input signal. If it is determined (step 620), when playing the screen thumbnail image, the H.264 codec 120-2 is commanded to read the H.264 compressed screen thumbnail image from MakerNote of the image file to be played and decompress H.264. Playback is performed (step 630).

The CPU 128 determines whether to play the main video or the thumbnail video according to the user input signal (step 640). When playing back the main video or the thumbnail video, the CPU 128 issues an instruction to the JPEG codec 120-1 to play back the image file. The JPEG compressed main video or thumbnail video is read from the JPEG video, and the JPEG video is decompressed and played back (step 650).

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

FIG. 2 is a schematic block diagram of the compression / decompression processing unit 120 shown in FIG. 1.

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

4 is a diagram illustrating 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 / decompression unit configured to compress the captured image into a thumbnail image and a main image; A second compression / decompression unit configured to compress the captured image into a screen thumbnail image; And And a controller configured to synthesize an image compressed by the first compression / decompression unit and the second compression / decompression unit to generate an image file. The method of claim 1, wherein the control unit And an image file including a thumbnail image and a main image compressed by the first compression / decompression unit, and a screen thumbnail image compressed by the second compression / decompression unit. The method of claim 1, wherein the control unit And the screen nail image is stored in a MakerNote data area including photographing information of the image file. The method of claim 3, wherein The thumbnail image and the main image compressed from the generated image file are released and reproduced in the first compression / decompression unit, and the thumbnail image compressed from the generated image file is decompressed by the second compression / decompression unit. An image compression / decompression device, characterized in that for playback. The apparatus of claim 4, wherein the first compression / decompression unit is a JPEG codec, and the second compression / decompression unit is an H.264 codec. As an operation method of the digital image processor, (a) first compressing the captured image to generate a thumbnail image and a main image; (b) generating a screen nail image by performing a second compression process on the captured image; And (c) synthesizing the first and second compressed images to generate an image file. The method of claim 6, wherein in step (c) And generating an image file including the first compressed thumbnail image and a main image and the second compressed screen thumbnail image. 8. The method of claim 7, wherein in step (c) And storing the screen thumbnail image in a MakerNote data area including shooting information in the image file. 9. The method of claim 8, wherein the first compression process is performed with a JPEG codec, and the second compression process is performed with an H.264 codec. The method of claim 9, The thumbnail image and the main image compressed from the generated image file are released by the JPEG codec, and the second screen thumbnail image compressed from the generated image file is reproduced by the H.264 codec. Image compression / decompression method.

Images