KR20070074029A - Digital image processing apparatus and method - Google Patents

Abstract

A digital image processing apparatus and a method therefor are provided to offer image data corresponding to respective image display modes. An object is photographed. An image signal of the photographed object is converted into digital image data(S101,S103). The converted digital image data are compressed and stored as an image data file in which small-sized image data are included in the digital image data. The compressed image data file has a JPEG(Joint Photographic Expert Group) file format. Main image data and thumbnail image data are compressed in the compressed image data file.

Description

 Digital image processing apparatus and method

1 is a data structure showing a file format of a conventional digital video.

FIG. 2 is a diagram illustrating an example of using an image of the still image file of FIG. 1. FIG.

FIG. 3 is a diagram illustrating an example of displaying an image of the image file format of FIG. 1; FIG.

4 is a block diagram illustrating a digital image processing apparatus according to an exemplary embodiment of the present invention.

5 is a data structure showing a file format of a digital image according to an embodiment of the present invention.

6 illustrates an example of displaying an image in a digital image file format according to an embodiment of the present invention.

7 is a flowchart illustrating a digital image compression method according to the present invention.

8 is a flowchart illustrating a compressed digital image output method according to the present invention.

9 is a flowchart showing an example of switching from a multi-view to a normal view according to the present invention.

<Explanation of symbols for the main parts of the drawings>

101 ... lens unit 103 ... image sensor

105.Analog / Digital Converter 107 ... Image Compressor

109 Preprocessing section 111 Memory section

113 Video Decoder 115 Video Decoder

117 Post-processing section 119 Display section

The present invention relates to a digital image processing apparatus, and more particularly, to a digital image processing apparatus and method for data processing for small screens.

The digital camera converts an analog image signal into a digital signal for signal processing, stores digital image data generated as a result of signal processing in a frame memory, and compresses the stored image data using software or a hardware compression circuit. Save it to the next storage medium.

In addition, in the digital camera, since the image photographed by the user is stored in the storage medium, the image can be reproduced and viewed on the screen through a liquid crystal display or the like without printing as a photograph. Therefore, the wrongly shot or unfavorable images can be removed from the storage medium or edited by the camera itself or a computer.

On the other hand, a thumbnail mode is provided to easily retrieve the captured image stored in the storage medium of the digital camera. When the thumbnail image mode is selected, the captured images stored in the storage medium are reduced in size and displayed on the liquid crystal display as a plurality of screens.If the user searches for and selects a desired screen among the plurality of screens, only the designated screen is enlarged. And displayed on the liquid crystal display in the size of the original image.

Such a digital camera function is applied to a portable terminal (mobile phone, PDA, MP3, broadcast terminal, etc.). For example, a still image or a moving picture can be taken using a digital camera provided in a mobile phone, and the captured image can be stored in an internal memory. The standard in which images are displayed in such a mobile terminal is the Joint Photographic Expert Group (JPEG). To date, the JPEG standard 10918-1 is used. In addition, a photo file taken with a digital camera records various things such as the date taken, shutter speed, aperture value, zoom ratio, resolution, flash use, and flash use. This information is recorded in the header part, and the rest is the same as a normal picture file. The file standard for recording this additional information is called EXIF.

1 is a diagram illustrating a data structure of an image file format.

Referring to FIG. 1, the image file format 10 is, for example, a JPEG file format, comprising: a header portion F1 having file information such as the type, compression ratio, resolution, etc. of the image file format; A main image unit (F2) for storing the captured image in a format corresponding to the predetermined image file format, compression ratio, and resolution; A thumbnail image part including an end part (not shown) for notifying the end of the image file and storing thumbnail images reduced at a predetermined rate with respect to the photographed image stored in the main image part F2 in some cases; F3). Here, the thumbnail image is stored using the EXIF standard.

There are three ways to view such image files according to the display mode. The first method is to search and view multiple pieces of image data as soon as possible with the Multi view. The second is a normal view (normal view), and view the image data size according to the display screen size (that is, the liquid crystal size). The third is an enlarged view, in which a detailed view of the detailed image data can be enlarged.

1 and 2, the image A ′ stored in the main image unit F2 of the image file format 10 is used as the image data A ′ for the enlarged view, and the thumbnail image A1 is the general view. It is used as image data A11 or multi-view image data A12.

3 is a diagram illustrating an example in which image data is used for each display mode.

As shown in (a) of FIG. 3, the main image data is displayed as the enlarged view image data A ′, and as shown in (b) (c), the thumbnail image data may be a normal view image A11 or a multi view image data ( A12). Here, in FIG. 3C, the cell size 31 of the multi view screen varies depending on the terminal, and is usually divided into M * N (or M) cell sizes into 4 screens, 8 screens, and 9 screens.

Here, in the general multi-view mode, the user can select one of 4 screens, 8 screens, 9 screens, or 16 screens to display thumbnail images. Of course, it can also be displayed in many other screens. In this way, the plurality of photographed images are reduced to thumbnail images and displayed on one screen so that the user can easily search for the desired images. In addition, the number of thumbnail images that can be displayed may vary according to the type of terminal or the size of the image display device, and the number of thumbnail image data displayed may be defaulted or changed by the user.

As such, the terminal is executing a multi-view so that multiple photos (for example, 4 to 16) can be viewed at once.

However, when viewing a multi view on a terminal or the like, the thumbnail image data present in each video file format is decoded at once and displayed in a multi view (for example, each size is 80 * 60), so that the time to process the multi view or There is a problem that the speed is delayed. In recent years, JPEG file sizes have been starting with QCIF (176 * 144) and have grown to 8M pixels.

Accordingly, as the size of the picture or the screen size increases, the size of the thumbnail image data also increases in proportion, which causes a problem that the aforementioned multi-view processing time or processing speed may be further delayed.

A first object of the present invention is to process digital image data for a small screen image.

It is a second object of the present invention to provide a digital image processing apparatus and method for providing image data corresponding to each display mode of an image.

A third object of the present invention is to provide a digital image processing apparatus and method for reconstructing and reconstructing at least two or more compressed image data into one image file.

A fourth object of the present invention is to provide a digital image processing apparatus and method for compressing and reconstructing an image file having an enlarged view image data, a general view image data, and a multi view image data.

A fifth object of the present invention is to store the main image data, thumbnail image data, small screen image data for multi-view as an image compression file using digital image data, and to restore and output the stored image data according to the viewing mode. To provide a digital image processing apparatus and method.

Digital image processing method according to the present invention for achieving the above object,

Photographing the subject; Converting the image signal of the photographed subject into digital image data; And compressing and storing the converted digital image data into an image data file including small screen image data.

Preferably, the compressed image data file is a JPEG file format, and the compressed image data file further includes main image data and thumbnail image data, and the main image data is compressed into an image for an enlarged or normal viewing mode. The thumbnail image data is compressed into an image for a normal viewing mode, and the small screen image data is compressed into a size for multi viewing.

According to another aspect of the present invention, there is provided a digital image processing method comprising: compressing and storing image data of each display mode of an image into an image file; And restoring and displaying the image data corresponding to the mode according to the display mode of the image.

Preferably, the image data for each display mode compresses main image data for enlarged view, thumbnail image data for general view, and small screen image data for multi view in JPEG compression format; The small screen image data is stored in a user command area in a header of a file format.

According to another aspect of the present invention, there is provided a method of processing a digital image, the method comprising: storing the compressed image data into one file, each of which is compressed into main image data, thumbnail image data, and small screen image data; Restoring and displaying one of the image data, the thumbnail image data, and the small screen image data in the file according to the display mode.

In addition, the digital image processing apparatus according to the present invention comprises: means for converting an input image into digital image data; Means for compressing the digital image data into a file format having at least three image data; Means for storing the compressed file format; Means for restoring one of the three stored digital image data in accordance with a viewing mode of the image; And means for displaying the restored digital image data on the screen.

Here, the compression and decompression means uses a JPEG compression and decompression method, and the compression means is the main image data for enlarged view, thumbnail image data for general view, and small screen image data for multi view from the photographed digital image data. Will be compressed.

Hereinafter, with reference to the accompanying drawings as follows.

4 is a block diagram illustrating a digital image processing apparatus according to an exemplary embodiment of the present invention. Referring to FIG. 4, the lens unit 101 through which light reflected from a subject is input, and the brightness and color of red (R), green (G), and blue (B) of an image input through the lens unit 101. An image sensor 103 for converting a value into an electrical signal, an analog / digital converter (ADC) 105 for converting a continuous video analog signal output from the image sensor 103 into a video digital signal, and the conversion A pre-processing unit 109 including an image compression unit 107 which compresses the digital image data into a JPEG (Joint Photographic Experts Group, hereinafter referred to as 'JPEG') format for easy storage, and the compressed digital image. A memory 111 for storing data, an image decoder 113 for decoding the compressed digital image data, and an image converter for converting the image decoded from the image decoder 113 into image data of an RGB method. Postman, including 115 Unit 117 and a display 119 for displaying the RGB image data, receives the user key is a signal configuration including the microcomputer 121 for controlling the respective units.

Here, the image compression unit 107 is a JPEG compression unit for JPEG compression of the captured digital image data into at least three different sized image data. The image data of different sizes includes a main image, a thumbnail image, and a small screen image.

In addition, the image decoding unit 113 decodes and outputs image data corresponding to the display mode. For example, when the display mode is an enlarged view, a normal view, or a multi view, the compressed main image, thumbnail image, and small screen image data for multi view are decoded and output.

A digital image processing apparatus and method according to an exemplary embodiment of the present invention configured as described above will be described with reference to the accompanying drawings.

First, the digital image processing apparatus is applied to a digital camera or a terminal equipped with the digital camera to compress and decode the photographed digital image data.

As shown in FIG. 4, the camera lens unit 101 adjusts the amount of light input to the image sensor 103 before the light reflected from the subject enters the image sensor 103. In addition, the image sensor 103 converts the brightness and color values of the R, G, and B values of the image input through the lens unit 101 into electrical signals. The image sensor 103 may include a complementary metal-oxide semiconductor (CMOS) sensor, a charge coupled device (CCD) sensor, or the like.

The analog-to-digital converter (ADC) 105 converts the continuous analog image signal output from the image sensor 103 into digital image data of 0 and 1. In this case, a YUV or YCbCr method is used to express color by dividing image data into luminance and chrominance components.

The image compression unit 107 compresses the digital image data converted by the analog / digital converter 105 by image compression (eg, JPEG) to make it easy to store. Here, the image compression unit 107 compresses the captured main image data, the thumbnail image data reduced from the image data, and the small screen image data for multi-viewing according to the JPEG compression method. The memory unit 111 also stores a file format of digital image data compressed by the image compression unit 107.

For example, the main image data is compressed using the photographed digital image data in the JPEG method, the thumbnail image data is compressed in the JPEG method into a reduced image than the size of the main image data, and the small screen image data is It is smaller than the thumbnail image data size or compressed in JPEG format for the size of multi view.

Here, the image file format may include a header part F11 having file information such as the type, compression ratio, resolution, etc. of the image file format 100; A main image unit (F12) for storing the captured image in a format according to the predetermined image file format, compression ratio, and resolution; A thumbnail image part including an end part (not shown) for notifying the end of the image file and storing thumbnail image data reduced in a predetermined ratio with respect to the photographed image stored in the main image part F12 in some cases. (F13) may be included.

In addition, the header unit F11 includes a small screen image storage unit F14 in a partial region. The small screen image storage unit F14 uses a portion of the user command area, that is, the prefix PREFIX of 0xFF and the code of 0xFE in the JPEG standard. The user command area can store up to 65 KB (ie, 65536 bytes) of data. The small screen image storage unit F14 is provided in a partial region of the header unit F11, so that output can be performed faster when the multi view is performed.

In addition, the size of the small screen image data stored in the small screen image storage unit F14 is stored in one display unit (that is, a cell) that is viewed in actual multi-view according to the type of the terminal. That is, the JPEG image corresponding to the actual multi-view size is stored in the small screen image data storage in a compressed state.

Alternatively, the image may be reduced and stored from the main image data, such as thumbnail image data, and the reduced ratio may be reduced to the same ratio as the thumbnail image data or to a smaller size. In this case, a time or speed delay at which small-screen image data is decoded may be set to a size that minimizes the multi-view.

Then, the compressed digital image data stored in the memory unit 111 is converted into YUV image data by the image decoding unit 113 and again by RGB image image data by the image conversion unit 115. An image is displayed on the display unit 119 such as an LCD.

Here, the preprocessing unit 109 is a process of processing before compressing the digital image data, and the post processor 117 is a process of processing after compressing the digital image data. In the terminal, the image compression and decoding unit is referred to as a codec, and may be referred to as an image processing unit including the analog-digital conversion unit, the image compression and decoding unit, and the image conversion unit.

The microcomputer 121 controls each unit according to the input of a user key, and in particular, controls the compression of the captured image data into data for each view module and saves it as a file, and corresponds to the view mode of the stored image file. Control of data conversion to decoding and output formats, and display of video data. It also controls to show the captured image in the preview format.

4 to 6, the operation of the image processing apparatus is as follows.

First, an image photographed using the camera lens unit 101 may be converted into digital image data through the preprocessor 109, and then temporarily stored and output in a preview mode or compressed and stored in the memory 111. have.

In the preview mode, when the user selects to save the image is compressed and stored. At this time, the stored image is compressed in the JPEG file format as described above and stored in the memory unit 111.

The compressed JPEG file format includes image data corresponding to at least three display modes, that is, main image data A, thumbnail image data A1, and small screen image data A12 as shown in FIG. It is compressed and stored in one JPEG file format 100.

Here, the small screen image data A2 is stored in the header unit F11 of the file format 100, the main image data A is stored in the main image storage unit F12, and the thumbnail image storage unit F13 is stored in the main image storage unit F12. ), Thumbnail image data A1 is stored. Here, the thumbnail image storage unit F13 may be included in the main image storage unit F12.

In addition, when a user requests a view of a photo, image data corresponding to each mode is restored and displayed according to the display mode.

If the display mode is an enlarged view mode, the main image data A 'displayed on the screen 130 is used as shown in FIGS. 5 and 6 (a). In the enlarged view mode, a specific area of the image data of the picture is used. When the center point to be enlarged is selected or an arbitrary area is designated to enlarge the image, the user decodes (ie, decodes) the main image data A stored in the main image storage unit F12 of the corresponding file format. The display screen is displayed on the display screen by scaling the coordinates of the selected point or area by the selected enlargement ratio. The reverse of this approach also applies to the reduced view mode, which allows you to view the original picture size or the smaller picture size.

In this case, when the thumbnail view data is displayed while the thumbnail image data in the normal view mode is displayed for the enlarged view mode, the enlarged view mode may be enlarged and displayed using the main image data of the portion. Alternatively, when the small screen image data and the main image data are displayed together on the display unit, when the enlargement / reduction based on the small screen image data is performed, the size of the main image data may be changed by the enlargement / reduction ratio.

In the normal viewing mode, as shown in FIGS. 5 and 6 (b), the thumbnail image data stored in the thumbnail image storage unit F13 in the image file format 100 is decoded to the actual screen size (ie, the liquid crystal size). (Ie, decoding) is output (A11) to the display screen 130.

In the multi view mode, as shown in FIGS. 5 and 6 (c), the small screen image data A2 stored in the small screen image data storage unit F14 in the header unit F11 of the image file format 100 may be used. After reading, the data is decoded (that is, decoded) and output to the display screen 130 (A21). Here, the multi-view cell size 131 is different depending on the type of the terminal and the size of the display screen, and can normally display from 4 to 16 at a time.

When one of the small screen image data displayed on the display unit is selected through the multi-view mode, the thumbnail image data of a file format having the small screen image data is restored and displayed. That is, when the small screen image to be displayed is selected, the display is switched to the normal view mode, and the thumbnail image data corresponding to the normal view mode is decoded and displayed on the display unit. When the enlarged view mode is selected using the image data displayed in the normal view mode, the main image data for the enlarged view mode is obtained and displayed.

The present invention provides a JPEG file data structure each including image data corresponding to at least three display modes, and compresses JPEG image data having at least three display mode-specific image data for such a JPGE file data structure. An image processing apparatus for decoding can be provided.

7 is a flowchart illustrating a compression method in the digital image processing method according to the present invention.

Referring to FIG. 7, the image photographed through the camera lens unit is converted into an electrical signal (S101). After converting the electrical analog signal into digital image data (S103), the main image data corresponding to the image captured by the JPEG compression method, the reduced thumbnail image data thereof, and the reduced image for multi viewing. Each is compressed into screen image data and stored as one file (S105).

That is, the image data file of the photographed picture includes main image data, thumbnail image data, and small screen image data compressed in the JPEG method, respectively. The small screen image data is stored in an area other than the image data storage area, for example, in the user command area of the header part. At this time, the data size stored in the user command area is at most 65K bytes or less.

8 is a flowchart illustrating a display method according to a display mode in the digital image processing method according to the present invention.

Referring to FIG. 8, when a user selects to view an image or a picture through a key input unit (not shown) (S111), the microcomputer in the system determines whether the key input signal is in an enlarged view mode (S113) or in a normal view mode (S117). It is determined whether the multi-view mode (S121). In this case, as a result of S113, in the enlarged view mode, the main video data in the video file format is restored (decoded) and displayed (S115). Thereafter, the displayed main image data is displayed while being partially enlarged or scaled to the original size by the user.

The image data for the enlarged view mode may initially display thumbnail image data in the normal view mode, and then, when the enlarged area is designated, the main image data may be restored (decoded) and displayed through enlargement of the designated area.

As a result of S117, in the normal viewing mode, the thumbnail image data stored in the image file format is restored and displayed (S119). In addition, in the multi-view mode (S121), the small-screen image data stored in the predetermined video file formats are respectively restored (decoded) and displayed for multi-view (S123).

9 is a flowchart showing an example of switching from the multi view mode to the normal view mode according to the present invention.

Referring to FIG. 9, when the multi view is selected by the user (S131), the small screen image data stored in the N file formats are restored and displayed in each of the N cell areas (S133).

In this case, when one image is selected from the N small screen image data (S135), the thumbnail image data of the selected image file format is restored and displayed (S137). In other words, the main video data stored in each file format is used for the enlarged view, the thumbnail video data is used for the general view, and the small screen video data is set for the multi view. Only the correct image data is restored and displayed.

According to the present invention, the multi-view image data is separately provided, thereby enabling quick retrieval of the image data using the multi-view, and providing an image processing apparatus that does not act as a heavy load on the system to a terminal equipped with a camera or a camera. Can be.

So far, the present invention has been described with reference to the preferred embodiments, and those skilled in the art to which the present invention pertains to the detailed description of the present invention and other forms of embodiments within the essential technical scope of the present invention. Could be implemented. Here, the essential technical scope of the present invention is shown in the claims, and all differences within the equivalent range will be construed as being included in the present invention.

According to the digital image processing apparatus and method according to the present invention, there is an effect that can minimize the delay time according to the multi-view by using the image data for the multi-view.

In addition, by providing the image data for each display mode, it is possible to minimize the restoration time of the image data according to each mode switching.

In addition, while retrieving image data from a camera or a terminal equipped with a camera, the multi-view function can be quickly processed.

Claims (19)

Photographing the subject; Converting the image signal of the photographed subject into digital image data; Compressing and storing the converted digital image data into an image data file including small screen image data; Digital image processing method comprising a. The method of claim 1, And the compressed image data file is a JPEG file format. The method of claim 1, And the main image data and the thumbnail image data are respectively compressed in the compressed image data file. The method of claim 3, wherein The main image data is used as an image for magnification or normal viewing, and the thumbnail image data is used as an image for normal viewing mode. The method of claim 1, And the small screen image data is used as a multi-view image. The method of claim 1, And reconstructing and outputting only the small screen image data from the file when the multi-view of the stored image data file is requested. The method of claim 1, The small screen image data is stored in a header area of a file format. The method of claim 1, And the small screen image data is stored in a user command area in a header of a file format. The method of claim 7, wherein The small screen image data is a maximum of 65K bytes. Compressing each of the main image data, the thumbnail image data, and the small screen image data by using the input digital image data, and storing the image data as an image file; Restoring and displaying one of main image data, thumbnail image data, and small screen image data in the file according to a display mode; Digital image processing method comprising a. The method of claim 10, The small screen image data is displayed in a multi view mode. The method of claim 11, And selecting thumbnail image data displayed in the multi-view mode to display thumbnail image data of the corresponding file. A main image storage unit in which main image data is compressed by using an input digital image, and a header unit in which small screen image data compressed for multi-view from the main image storage unit is stored; Digital image data structure comprising a. The method of claim 13, Wherein the compression method uses a JPEG compression method. The method of claim 13, And the main image storage unit further comprises a thumbnail image storage unit in which thumbnail image data is compressed. Means for converting the input image into digital image data; Means for compressing the digital image data into a file format having at least three image data; Means for storing the compressed file format; Means for restoring one of the three stored digital image data in accordance with a viewing mode of the image; Means for displaying the restored digital image data on a screen; Digital image processing apparatus comprising a. The method of claim 16, And said compression and decompression means uses JPEG compression and decompression. The method of claim 16, And the compression unit compresses the photographed digital image data into enlarged view main image data, general view thumbnail image data, and multi view small screen image data. The method of claim 16, And a camera lens unit for photographing a subject and outputting the subject to the digital conversion unit for the input image.

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