KR100802425B1 - Method of processing color stopping image in wireless multimedia messaging service - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a color still image processing method in a wireless multimedia messaging service and a computer readable recording medium storing a program for realizing the method.

2. The technical problem to be solved by the invention

An object of the present invention is to provide a color still image processing method for minimizing image quality degradation of a color still image encoded in a multimedia messaging service, and a computer readable recording medium having recorded thereon a program for realizing the method.

3. Summary of Solution to Invention

The present invention relates to a color still image processing method in a wireless terminal during a wireless multimedia messaging service, comprising: constructing a mapping table for increasing color information of a predetermined color image and decreasing information amount other than the predetermined color value for color still images; ; Compressing the imaging information by applying the mapping table to the still image (photographing information) captured by the wireless terminal by increasing the information amount of the predetermined dye and reducing the amount of information other than the predetermined dye by the wireless terminal; And encoding the compressed captured image information using a known still image compression algorithm, and storing / transmitting the encoded image information along with a corresponding table number.

4. Important uses of the invention

The present invention is used for wireless multimedia services.

Wireless Multimedia Services, Still Images, Compression, Portrait, Background Photos

Description

Color still image processing method in wireless multimedia messaging service {Method of processing color stopping image in wireless multimedia messaging service}             

1 is an exemplary configuration of a wireless multimedia messaging service system to which the present invention is applied.

FIG. 2 is a diagram illustrating one embodiment of a color decrement mapping table in which the amount of information of a specific pigment used in the present invention is increased and the amount of information of the remaining pigments is decreased. FIG.

3 is a flowchart illustrating an embodiment of a color still image processing method according to the present invention;

* Explanation of symbols for the main parts of the drawings

10,20: Wireless terminal

The present invention relates to a color still image processing method in a wireless multimedia messaging service and a computer-readable recording medium recording a program for realizing the method. Particularly, the present invention relates to a PNG (Portable Network Graphics) in a wireless terminal in a wireless multimedia messaging service. ) Is to minimize the error that occurs when displaying encoded still images such as GIF (Graphics Interchange Format) at low quality color depth.

PNG is a video file format developed mainly in consideration of handling graphic data in a network environment such as the Internet. It is more efficient than the GIF format, can be transparent, and can handle 24-bit color images. Therefore, the World Wide Web Consortium (W3C), the World Wide Web Standardization Organization, recommends it as one of the graphic formats for the WWW, and supports the latest versions of major World Wide Web browsers such as Netscape Navigator and Internet Explorer.

GIF is an image and graphic standard for general computers. It converts high-resolution information into a look-up table using a palette, and expresses color information during the process. Index values are compressed with the "Lempel-Ziv-Welch (LZW) algorithm".

Joint Photographic Expert Group (JPEG) is a standard for the compression of continuous-tone still images. This algorithm aims to convert GIF, which is widely used for displaying image and graphic information to the World Wide Web (WWW) of the Internet, to JPEG, which can reduce the file size by 10-50%.                         

Currently, wireless terminals capable of receiving multimedia messaging services will be equipped with a camera (CMOS 100,000 pixel class) device and a color LCD (color depth 8 bit, or 256 colors). In this case, a color still image input through the camera uses a compression algorithm such as PNG, JPEG, or GIF for storage or transmission. In this case, since it is expressed in 256 colors limited to a limited still image size (for example, 128 × 96 (SQCIF), 160 × 120, or 176 × 144 (QCIF)), the image quality is deteriorated. For example, the skin color of the face deteriorates in the portrait and appears as red spots such as skin diseases.

Therefore, a method for minimizing image quality deterioration of color still images in a multimedia messaging service is required.

SUMMARY OF THE INVENTION The present invention has been proposed to meet the above-mentioned demands, and includes a color still image processing method for minimizing image quality deterioration of a color still image encoded in a multimedia messaging service and a computer recording a program for realizing the method. The purpose is to provide a recording medium that can be read by.

In order to achieve the above object, the present invention provides a method for processing a color still image in a wireless terminal during a wireless multimedia messaging service, wherein the amount of information of a predetermined color is increased and the amount of information other than the predetermined color is reduced for a color still image. Constructing a mapping table; Compressing the imaging information by applying the mapping table to the still image (photographing information) captured by the wireless terminal by increasing the information amount of the predetermined dye and reducing the amount of information other than the predetermined dye by the wireless terminal; And encoding the compressed captured image information using a known still image compression algorithm, and storing / transmitting the encoded image information along with a corresponding table number.

In addition, the present invention relates to a color still image processing method in a wireless terminal in a wireless multimedia messaging service, comprising a mapping table in which an amount of information of a predetermined dye is increased and a amount of information other than the predetermined dye is reduced for a color still image. Making; The wireless terminal determines the main pigment of the partial screen centered on the center of the still image (photographing information) captured by the camera, thereby increasing the amount of information on the main pigment and reducing the amount of information on the pigments other than the main pigment. Selecting a mapping table; Applying the corresponding mapping table to image information, compressing the image information by increasing the amount of information of the main pigment and reducing the amount of information other than the main pigment; And encoding the compressed captured image information using a known still image compression algorithm, and storing / transmitting the encoded image information along with the corresponding table number.

In addition, the present invention provides a color still image processing method in a wireless terminal in a wireless multimedia messaging service, comprising a mapping table in which the amount of information of a predetermined dye is increased and the amount of information other than the predetermined dye is reduced for the color still image. Making; Determining, by the wireless terminal, the type of still image (photographing information) captured by the camera; As a result of the determination, in the case of the portrait photograph, by applying a mapping table in which the amount of information on the human skin pigment is increased and the amount of information on the pigment other than the human skin pigment is applied, the amount of information on the human skin pigment is increased. A first compression step of compressing the captured image information by reducing the amount of information other than the human skin pigment; As a result of the determination, in the case of the background picture, the main pigment of the partial screen is judged centered on the center of the still image (photographing information) photographed by the camera, so that the amount of information on the main pigment is increased, A second compression step of compressing the imaging information by applying a mapping table in which the amount of information on the information is reduced, increasing the information amount of the main dye and reducing the amount of information other than the main dye; And encoding the captured image information compressed in the first and second compression steps using a known still image compression algorithm, and storing / transmitting the encoded image information together with the corresponding table number. .

The present invention for achieving the above object, for a wireless multimedia messaging service, to a wireless terminal provided with a processor, a mapping table for increasing the amount of information of a predetermined color, and for reducing the amount of information other than the predetermined color for a color still image; Constructing function; A function of compressing the imaging information by applying the mapping table to the still image (photographing information) captured by the wireless terminal by increasing the amount of information of the predetermined dye and reducing the amount of information other than the predetermined dye; And a computer readable recording medium having recorded thereon a program for realizing a function of encoding the compressed captured image information using a known still image compression algorithm and storing / transmitting the encoded image information along with a corresponding table number. do.

In addition, the present invention provides a wireless terminal equipped with a processor for a wireless multimedia messaging service, the function of configuring a mapping table for increasing the amount of information of a predetermined dye and the amount of information other than the predetermined dye for a color still image; The wireless terminal determines the main pigment of the partial screen centered on the center of the still image (photographing information) captured by the camera, thereby increasing the amount of information on the main pigment and reducing the amount of information on the pigments other than the main pigment. Selecting a mapping table; Applying the corresponding mapping table to sensing information to increase the amount of information of the main dye and to reduce the amount of information other than the main dye to compress the sensing information; And a computer readable recording medium having recorded thereon a program for realizing a function of encoding the compressed captured image information using a known still image compression algorithm and storing / transmitting the encoded image information along with a corresponding table number. do.

In addition, the present invention provides a wireless terminal equipped with a processor for a wireless multimedia messaging service, the function of configuring a mapping table for increasing the amount of information of a predetermined dye and the amount of information other than the predetermined dye for a color still image; A function of determining, by the wireless terminal, the type of still image (photographing information) captured by the camera; As a result of the determination, in the case of the portrait photograph, by applying a mapping table in which the amount of information on the human skin pigment is increased and the amount of information on the pigment other than the human skin pigment is applied, the amount of information on the human skin pigment is increased. A first compression function of compressing the captured image information by reducing the amount of information other than the human skin pigment; As a result of the determination, in the case of the background picture, the main pigment of the partial screen is judged centered on the center of the still image (photographing information) photographed by the camera, so that the amount of information on the main pigment is increased, A second compression function for applying the mapping table in which the amount of information on the information is reduced to increase the information amount of the main dye and reduce the amount of information other than the main dye to compress the captured image information; And a program for encoding a captured image information compressed through the first and second compression functions using a known still image compression algorithm, and for storing / transmitting the encoded image information along with the corresponding table number. Provide a computer readable recording medium.

The present invention is to wirelessly minimize the errors that occur when displaying the encoded still image, such as PNG, GIF, etc. at a low depth color depth in a wireless terminal for a wireless multimedia messaging service, When compressing 24-bit color input to the camera attached to the terminal into 8-bit, increase the amount of color information on the face of a portrait or a specific object to be expressed, and instead reduce the amount of color information on other backgrounds, Deterioration in image quality is made less detectable while having the same still image data.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration of a wireless multimedia messaging service system to which the present invention is applied.

The wireless terminals 10 and 20 are terminals capable of receiving multimedia messaging services, and are assumed to be equipped with a camera (CMOS 100,000 pixel class) device and a color LCD (8-bit color or 256 colors). In particular, the wireless terminal 10, 20 increases the amount of color information for the face of a portrait or a specific object to be expressed when compressing the 24-bit color input to the camera attached to the terminal into 8 bits, and instead of Algorithm for reducing the amount of color information on the background of the image is embedded, so that the same still image data can be compensated to detect less degradation of the image quality.

The algorithm increases the amount of color information for a face of a person's face or a specific object to be expressed when compressing or storing a 24-bit color still image such as PNG, GIF, JPEG, etc. into 8 bits, and instead, Reduce the amount of color information for

In general, a color is represented by a method of “RGB”, which is a method of expressing a color by mixing colors of red light (R), green light (G), and blue light (B), which are three elements of light.

The signal input from the camera of the wireless terminals 10 and 20 has a signal level of 8 bits for each of R, G, and B (24-bit color in total). In order to compress it to 256 colors of 8 bits, a standardized Decrease Mapping Table (or Pallet Table) is applied. However, as described above, in the case of skin coloration of a portrait, inappropriate expression (for example, red spots, etc.) may occur due to deterioration of image quality.

In this case, as shown in FIG. 2, when the 24-bit R, G, and B colors are compressed to 256 colors of 8 bits, the color reduction mapping table increases the amount of specific pigment information and decreases the amount of information on the remaining pigments. By applying a mapping table, the amount of color information of a specific object (for example, facial skin color, skin color, etc.) of a person's photograph is increased (for example, if the bit increases by 1 bit, the expressive color increases by 2 times). When the amount of color information of the dye (for example, the background screen) is reduced, the service subscriber who receives the still image message can minimize the rejection caused by the deterioration of the image quality.

3 is a flowchart illustrating an embodiment of a method for processing a color still image according to the present invention, which illustrates a procedure of increasing a specific amount of pigment information and reducing the amount of information on remaining pigments in a wireless terminal.

The service menu implemented on the wireless terminals 10 and 20 has a total of two options (for example, "1. portrait photo" and "2. background photo").

First, when a subscriber of a multimedia messaging service presses a shooting menu of a still image with a camera attached to the wireless terminals 10 and 20, the subscriber asks whether the still image to be photographed is a portrait or a background image (301).

If the subscriber selects a portrait picture (302), when taking a portrait picture through a camera (303), and compressing the captured 24-bit portrait still image to an 8-bit portrait still image, it is shown in FIG. By applying the Color Decreasing Mapping Table (e.g., defined as Table 1), which increases the amount of information on facial skin color as shown in FIG. Compression (BMP format) (305). Thereafter, encoding is performed using the existing still image compression algorithm JPEG, PNG, GIF, and the like (306) and stored or transmitted together with the corresponding table number (311).

On the other hand, if the subscriber selects the background picture (302), the background picture is taken by the camera (307), and the partial screen (for example, 80 × 60 centered around the center of the entire 24-bit background still image) After determining the main pigments of the size, the pre-prepared Color Decreasing Mapping Table (e.g., Table 2 for increasing the amount of red information, Table 3 for increasing the amount of blue information, etc.) After selection (308), a color reduction mapping table (Color Decreasing Mapping Table) in which the information amount of the corresponding dye is increased is applied (309), and compressed (256) into 256 colors (310). Thereafter, encoding is performed using the existing still image compression algorithm JPEG, PNG, GIF, and the like (306) and stored or transmitted together with the corresponding table number (311).

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill.

As described above, the present invention increases the amount of color information for a face or a specific object of a portrait, thereby reducing the deterioration of still image quality caused in a limited environment (limited still image size, limited color depth). have.

In addition, the present invention has the effect of reducing the amount of color information for the background image while maintaining the same amount of still image data.

Claims (11)

A color still image processing method in a wireless terminal in a wireless multimedia messaging service, For a color still image, constructing a mapping table in which the amount of information of a predetermined dye is increased and the amount of information other than the predetermined dye is reduced; Compressing the imaging information by applying the mapping table to the still image (photographing information) captured by the wireless terminal by increasing the information amount of the predetermined dye and reducing the amount of information other than the predetermined dye by the wireless terminal; And Encoding the compressed image information using a known still image compression algorithm, and storing / transmitting the encoded image information together with a corresponding table number. Color still image processing method for a wireless multimedia messaging service comprising a. The method of claim 1, The still image, Color still image processing method of the wireless multimedia messaging service, characterized in that the person photographed information photographed by the camera. The method of claim 1, The predetermined dye, A color still image processing method in a wireless multimedia messaging service, characterized by human skin color. A color still image processing method in a wireless terminal in a wireless multimedia messaging service, For a color still image, constructing a mapping table in which the amount of information of a predetermined dye is increased and the amount of information other than the predetermined dye is reduced; The wireless terminal determines the main pigment of the partial screen centered on the center of the still image (photographing information) captured by the camera, thereby increasing the amount of information on the main pigment and reducing the amount of information on the pigments other than the main pigment. Selecting a mapping table; Applying the corresponding mapping table to image information, compressing the image information by increasing the amount of information of the main pigment and reducing the amount of information other than the main pigment; And Encoding the compressed image information using a known still image compression algorithm, and storing / transmitting the encoded image information together with a corresponding table number. Color still image processing method for a wireless multimedia messaging service comprising a. The method of claim 4, wherein The still image, Color still image processing method of the wireless multimedia messaging service, characterized in that the background picture information taken by the camera. A color still image processing method in a wireless terminal in a wireless multimedia messaging service, For a color still image, constructing a mapping table in which the amount of information of a predetermined dye is increased and the amount of information other than the predetermined dye is reduced; Determining, by the wireless terminal, the type of still image (photographing information) captured by the camera; As a result of the determination, in the case of the portrait photograph, by applying a mapping table in which the amount of information on the human skin pigment is increased and the amount of information on the pigment other than the human skin pigment is applied, the amount of information on the human skin pigment is increased. A first compression step of compressing the captured image information by reducing the amount of information other than the human skin pigment; As a result of the determination, in the case of the background picture, the main pigment of the partial screen is judged centered on the center of the still image (photographing information) photographed by the camera, so that the amount of information on the main pigment is increased, A second compression step of compressing the imaging information by applying a mapping table in which the amount of information on the information is reduced, increasing the information amount of the main dye and reducing the amount of information other than the main dye; And Encoding the captured image information compressed in the first and second compression steps using a known still image compression algorithm, and storing / transmitting the encoded image information together with the corresponding table number. Color still image processing method for a wireless multimedia messaging service comprising a. The method according to any one of claims 1 to 6, The wireless terminal, And a terminal for supporting a wireless multimedia messaging service equipped with the camera and a color display device. The method of claim 7, wherein The mapping table is, When the 24-bit red light (R), green light (G), and blue light (B) color information is compressed into 8-bit 256 color information, the color reduction increases the information amount of the predetermined dye and decreases the amount of information other than the predetermined dye. A color still image processing method in a wireless multimedia messaging service, characterized in that it is a Color Decreasing Mapping Table. In a wireless terminal having a processor for a wireless multimedia messaging service, For a color still image, a function of constructing a mapping table in which the amount of information of a predetermined dye is increased and the amount of information other than the predetermined dye is reduced; A function of compressing the imaging information by applying the mapping table to the still image (photographing information) captured by the wireless terminal by increasing the amount of information of the predetermined dye and reducing the amount of information other than the predetermined dye; And A function of encoding the compressed image information using a known still image compression algorithm and storing / transmitting the encoded image information together with a corresponding table number. A computer-readable recording medium having recorded thereon a program for realizing this. In a wireless terminal having a processor for a wireless multimedia messaging service, For a color still image, a function of constructing a mapping table in which the amount of information of a predetermined dye is increased and the amount of information other than the predetermined dye is reduced; The wireless terminal determines the main pigment of the partial screen centered on the center of the still image (photographing information) captured by the camera, thereby increasing the amount of information on the main pigment and reducing the amount of information on the pigments other than the main pigment. Selecting a mapping table; Applying the corresponding mapping table to sensing information to increase the amount of information of the main dye and to reduce the amount of information other than the main dye to compress the sensing information; And A function of encoding the compressed image information using a known still image compression algorithm, and storing / transmitting the encoded image information together with a corresponding table number. A computer-readable recording medium having recorded thereon a program for realizing this. In a wireless terminal having a processor for a wireless multimedia messaging service, For a color still image, a function of constructing a mapping table in which the amount of information of a predetermined dye is increased and the amount of information other than the predetermined dye is reduced; A function of determining, by the wireless terminal, the type of still image (photographing information) captured by the camera; As a result of the determination, in the case of the portrait photograph, by applying a mapping table in which the amount of information on the human skin pigment is increased and the amount of information on the pigment other than the human skin pigment is applied, the amount of information on the human skin pigment is increased. A first compression function of compressing the captured image information by reducing the amount of information other than the human skin pigment; As a result of the determination, in the case of the background picture, the main pigment of the partial screen is judged centered on the center of the still image (photographing information) photographed by the camera, so that the amount of information on the main pigment is increased, A second compression function for applying the mapping table in which the amount of information on the information is reduced to increase the information amount of the main dye and reduce the amount of information other than the main dye to compress the captured image information; And Encoding image information compressed through the first and second compression functions using a known still image compression algorithm, and storing / transmitting the encoded image information together with the corresponding table number. A computer-readable recording medium having recorded thereon a program for realizing this.

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