JP2010218570A - Game system, information memory medium, and production method for compressed data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a game system capable of producing a real and high quality image while applicable memory capacity of data is restrained, an information memory medium, and a compression method. <P>SOLUTION: Color data is obtained by extending compressed data CP1 of color data of an original image with a decoding section, compressed data CP2 produced by setting and compressing the α value of the original image as color data is extended by the decoding section for color data, and obtained extension data EX2 is set up as an α value. Then, a game image is created by performing an α composition treatment using the color data and the α value. The α value is set up as a value according to gradation of a green color component of the extension data. A size is reduced in lateral and longitudinal directions at the time of compression, and the size is returned to the original size by expanding the size at the time of extension. Data for hit check, data for motion control of an object, data for image control of an object and data for a depth value are used as first data of the target for compression and extension. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a game system, an information storage medium, and a compressed data generation method.

  Conventionally, a game system that generates an image that can be seen from a given viewpoint in an object space that is a virtual three-dimensional space is known, and is popular as a device that can experience so-called virtual reality. Taking a game system that can enjoy a role-playing game (RPG) as an example, a player manipulates a character (object) that is his or her own character to move it on the map and play against an enemy character, Enjoy games by interacting with characters and visiting various towns.

Japanese Patent Laid-Open No. 10-098719 JP-A-4-167189

  Now, in such a game system, it is an important technical problem to generate a more realistic and high-quality image in order to improve the virtual reality of the player.

  On the other hand, as a reflective effect of improving the realness and quality of an image, there arises a problem that the used storage capacity of data necessary for image generation increases. In order to solve such a problem, in this type of game system, the color data (RGB) is compressed and stored in an information storage medium such as a DVD or CD, and is compressed when the image is displayed. The obtained color data is expanded (developed), and an image is generated based on the obtained color data. For this reason, many home game systems and the like include a decoding unit for decompressing compressed color data.

  However, this type of game system has a compressed data decoding unit that targets only color data (RGB) for decompression processing, and other data such as alpha values used for translucent processing of display objects. Not subject to decompression processing. Therefore, the color data can be compressed and stored in an information storage medium or the like, but other data such as the α value cannot be compressed and stored, and the storage capacity of the data is large. There is a problem of increasing.

  The present invention has been made in view of the problems as described above. The object of the present invention is to provide a game system, an information storage medium, and an information storage medium that can generate a real and high-quality image while suppressing the storage capacity of data. It is to provide a compression method.

(1) The present invention is a game system having decoding means for expanding compressed color data,
Decompressed data in which compressed data generated by setting and compressing first data different from color data as color data is decompressed using the decoding means, and the obtained decompressed data is set as first data Processing means;
Means for performing a given process for generating an image using the set first data,
The first data is a depth value.

  The present invention also relates to an information storage medium that can be read by a computer and stores a program for causing the computer to function as each of the above-described means.

(2) In the game system and information storage medium according to the present invention,
The means for performing the given process is:
You may make it perform hidden surface deletion based on the set depth value.

(3) In the game system and information storage medium according to the present invention,
The decompressed data processing means is
The compressed data generated by setting and compressing the depth value included in the movie data as color data is expanded using the decoding means, and the obtained expanded data is set as the depth value.
The means for performing the given process is:
The hidden surface may be erased based on the set depth value and the depth value of the moving object, and an image in which the movie and the moving object are combined may be generated.

(4) The present invention is a method for generating compressed data used in a game system having a decoding means for expanding compressed color data,
The first data different from the color data to be decompressed by the decoding means is set as color data and compressed to generate compressed data used in the game system,
The first data is depth value data.

(5) In the compressed data generation method according to the present invention,
The depth value included in the movie data may be set as color data and compressed to generate compressed data used in the game system.

It is an example of a functional block diagram of the game system of this embodiment. It is an example of the game image produced | generated by this embodiment. It is an example of the picture of each part which comprises a game image. It is an example of the image data which comprises the picture of each part. It is a figure for demonstrating the principle of this embodiment. It is a figure for demonstrating the method of setting (alpha) value to the value according to the gradation of the color component which expansion | extension data contains, and setting the green component which expansion | extension data contains to (alpha) value. It is a figure for demonstrating the method of scaling the data of alpha value to the horizontal direction and the vertical direction. FIGS. 8A, 8 </ b> B, and 8 </ b> C are diagrams for explaining a method of using hit check data and movement control data as the first data. FIGS. 9A and 9B are diagrams for explaining a method of using image control data as the first data. It is a figure for demonstrating the method of using a depth value (Z value) as 1st data. FIGS. 11A and 11B are also diagrams for explaining a method using a depth value (Z value) as the first data. It is a figure for demonstrating index color and texture mapping. It is a figure for demonstrating the method of converting the color data of G plane into alpha value using the LUT for index color and texture mapping effectively. It is a figure for demonstrating the method of texture mapping to the polygon of a division | segmentation block size using LUT. It is a flowchart shown about the detailed example of the process of this embodiment. It is a flowchart shown about the detailed example of the process of this embodiment. It is a figure for demonstrating the detailed example of the process of this embodiment. It is a figure for demonstrating the detailed example of the process of this embodiment. It is a figure which shows an example of the structure of the hardware which can implement | achieve this embodiment. 20A, 20B, and 20C are diagrams showing examples of various types of systems to which the present embodiment is applied.

  In order to solve the above-described problem, the present embodiment is a game system having a decoding unit that decompresses compressed color data, and sets and compresses first data different from the color data as color data. Means for decompressing the generated compressed data using the decoding means, setting the obtained decompressed data as first data, and generating the image using the set first data; Means for performing a given process. The information storage medium according to the present embodiment is an information storage medium that can be used by a computer, and includes a program for causing the computer to realize the above means. The program according to the present embodiment is a program that can be used by a computer (a program embodied in an information storage medium or a carrier wave), and includes a module for causing the computer to realize the above means.

  In this embodiment, compressed data generated by setting and compressing first data different from color data as color data is prepared (for example, read from an information storage medium or a network). Here, the first data is data other than color data such as α value, hit check data, object movement control data, object image control data, or depth value. This is data set in association with (texel).

  In this embodiment, the prepared compressed data is decompressed using the color data decoding means, and the obtained decompressed data is set (converted) to the first data. Then, using the set first data, various processes for generating an image (α composition process, hit check process, object movement control process, object image control process, hidden surface removal process, or texture mapping) Etc.) is performed.

  By doing so, it becomes possible to effectively decompress the compressed data of the first data different from the color data by effectively using the decoding means provided for decompressing the color data. As a result, it is possible to generate a real and high-quality image using the first data while suppressing the storage capacity of the data.

  In the game system, information storage medium, and program according to the present embodiment, the first data is an α value, and the first compressed data generated by compressing the color data included in the image data is decoded. The second compressed data generated by setting the α value included in the image data to the color data and compressing it is expanded and obtained using the decoding means. The obtained decompressed data is set to an α value, and an α composition process using the obtained color data and the α value is performed. In this way, it becomes possible to decompress the compressed data of the α value by effectively using the decoding means provided for decompressing the color data, and the color data and the α value (for example, the texture having the color data and the α value). Realistic and high-quality images can be generated using.

  The game system, information storage medium, and program according to the present embodiment set the first data to a value corresponding to the gradation (grayscale) of the color component included in the decompressed data obtained by the decoding means. It is characterized by that. In this way, a realistic image can be generated using the first data whose value changes finely.

  The game system, information storage medium, and program according to the present embodiment are characterized in that the green component included in the decompressed data obtained by the decoding means is set as the first data. In this way, it is possible to generate a high-quality image while minimizing information deterioration of the first data due to compression / decompression.

  The game system, information storage medium, and program according to the present embodiment are generated by compressing the compressed data after the size of at least one of the horizontal direction and the vertical direction is reduced, and are obtained by the decoding unit. The decompressed data is characterized in that at least one of the horizontal direction and the vertical direction is enlarged and returned to the original size. In this way, for example, when the first data is data for which deterioration of information does not cause much problem, the used storage capacity of the data can be greatly saved.

  In the game system, information storage medium, and program according to the present embodiment, the first data includes hit check data, object movement control data, object image control data, and depth value data. It is characterized by being at least one. In this way, appropriate hit check processing, object movement control processing, object image control processing, or hidden surface erasure processing can be realized while saving the data storage capacity used.

  In addition, the game system, the information storage medium, and the program according to the present embodiment obtain a value of first data at each position of the object, and perform processing on the object based on the obtained value of the first data. And In this way, for example, when the first data is set on the map on which the object moves, the value of the first data is obtained based on the position of the object on the map. Based on the value, various processes such as movement control, image control, or event control can be performed on the object.

  The game system, information storage medium, and program according to the present embodiment are characterized in that the processing for an object is at least one of processing for controlling movement of the object and processing for controlling an image of the object. This makes it possible to realize real and highly accurate object movement control and image control while saving the storage capacity of the first data.

  The game system, information storage medium, and program according to the present embodiment set decompressed data obtained by decompressing the compressed data as an index number of a lookup table for index color / texture mapping, and decompressed data. The index color / texture mapping is performed on the virtual object using the look-up table in which is set as the index number, and the decompressed data is set as the first data. In this way, the process of setting the decompressed data as the first data can be performed in a single batch of texture mapping, for example, and the process can be made more efficient.

  The virtual object is preferably a primitive surface such as a polygon, but may be a three-dimensional object. The virtual object is preferably not displayed on the screen, but may be displayed.

  Further, the present embodiment is a method for generating compressed data used in a game system having a decoding means for expanding compressed color data, and is a first method different from color data to be subjected to expansion processing of the decoding means. The data is set as color data and compressed to generate compressed data used in the game system.

  According to the present embodiment, the first data different from the color data is compressed, the generated compressed data is read into the game system via the information storage medium or the network, and the color data decoding means is used. It can be stretched.

  The first data may be compressed in real time during the game process.

  In the present embodiment, the first data is an α value, the color data included in the image data is compressed to generate the first compressed data, and the α value included in the image data is set as the color data. And compressed to generate second compressed data. In this way, not only the color data but also the α value can be regarded as color data and can be compressed, and the data amount of the compressed data can be further reduced.

  In addition, the present embodiment is characterized in that the first data is set and compressed to color data of gradation according to the value of the first data. In this way, it is possible to properly compress the first data whose value changes finely.

  In the present embodiment, the first data is compressed after the size of at least one of the horizontal direction and the vertical direction is reduced. In this way, for example, when the first data is data in which deterioration of information does not cause a problem, the amount of compressed data can be further reduced.

  In the present embodiment, the first data is at least one of hit check data, object movement control data, object image control data, and depth value data. . In this way, not only color data but also hit check data, object movement control data, object image control data, and depth value data can be compressed in a compact manner.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1. Configuration FIG. 1 shows an example of a functional block diagram of a game system (image generation system) of the present embodiment. In this figure, the present embodiment only needs to include at least the processing unit 100 (or include the processing unit 100 and the storage unit 170), and the other blocks can be optional components.

  The operation unit 160 is for a player to input operation data, and the function can be realized by hardware such as a lever, a button, a microphone, or a housing.

  The storage unit 170 serves as a work area such as the processing unit 100 or the communication unit 196, and its function can be realized by hardware such as a RAM.

  An information storage medium 180 (storage medium usable by a computer) stores information such as programs and data, and functions thereof are an optical disk (CD, DVD), a magneto-optical disk (MO), a magnetic disk, and a hard disk. It can be realized by hardware such as a magnetic tape or a memory (ROM). The processing unit 100 performs various processes of the present invention (this embodiment) based on information stored in the information storage medium 180. That is, the information storage medium 180 stores a program for causing a computer to implement (execute, function) the means of the present invention (this embodiment) (particularly, the blocks included in the processing unit 100). Includes multiple modules (including objects in object orientation).

  Part or all of the information stored in the information storage medium 180 is transferred to the storage unit 170 when the system is powered on. The information storage medium 180 also includes a program for performing the processing of the present invention, image data, sound data, shape data of the display object, information for instructing the processing of the present invention, or processing in accordance with the instructions. Information etc. can be included.

  The display unit 190 outputs an image generated according to the present embodiment, and the function thereof can be realized by hardware such as a CRT, LCD, or HMD (head mounted display).

  The sound output unit 192 outputs the sound generated by the present embodiment, and its function can be realized by hardware such as a speaker.

  The portable information storage device 194 stores player personal data, game save data, and the like. As the portable information storage device 194, a memory card, a portable game device, and the like can be considered.

  The communication unit 196 performs various controls for communicating with the outside (for example, a host device or other game system), and functions thereof are various processors, hardware such as a communication ASIC, It can be realized by a program.

  A program (data) for realizing each means of the present invention (this embodiment) is distributed from the information storage medium of the host device (server) to the information storage medium 180 via the network and the communication unit 196. May be. Use of such an information storage medium of the host device (server) is also included in the scope of the present invention.

  The processing unit 100 (processor) performs various processes such as a game process, an image generation process, and a sound generation process based on operation data from the operation unit 160, a program, and the like. In this case, the processing unit 100 performs various processes using the main storage unit 172 in the storage unit 170 as a work area.

  Here, game processing performed by the processing unit 100 includes coin (price) acceptance processing, various mode setting processing, game progress processing, selection screen setting processing, position of an object (one or more primitive surfaces), Processing for obtaining a rotation angle (rotation angle about X, Y or Z axis), processing for moving an object (motion processing), processing for obtaining a viewpoint position (virtual camera position) and a line-of-sight angle (virtual camera rotation angle), Processing to place objects such as map objects in the object space, hit check processing, processing to calculate game results (results, results), processing for multiple players to play in a common game space, game over processing, etc. Can think.

  Further, the processing unit 100 performs various image processing based on the game processing result, generates a game image, and outputs the game image to the display unit 190. For example, when generating a so-called three-dimensional game image, first, geometric processing such as coordinate transformation, clipping processing, perspective transformation, or light source calculation is performed, and drawing data (primitive surface Position coordinates, texture coordinates, color (brightness) data, normal vectors, α values, etc.) given to the constituent points (vertices) are created. Based on the drawing data (primitive surface data), the image of the object (one or a plurality of primitive surfaces) after the geometry processing is stored in the drawing buffer 174 (frame buffer, work buffer, or other pixel unit image information). ) Is drawn. As a result, an image that can be seen from a given viewpoint (virtual camera) in the object space is generated.

  Further, the processing unit 100 performs various sound processing based on the above-described game processing result, generates game sound such as BGM, sound effect, or sound, and outputs the game sound to the sound output unit 192.

  The function of the processing unit 100 is more preferably realized by a combination of hardware (a processor such as a CPU or DSP or an ASIC such as a gate array) and a program (such as a game program or firmware). However, all of the functions of the processing unit 100 may be realized by hardware, or all of them may be realized by a program.

  The processing unit 100 includes a decoding (decompression) unit 110, an expanded data processing unit 120, a hit check unit 122, a movement control unit 124, an image control unit 126, a texture mapping unit 130, a hidden surface removal unit 132, and an α synthesis unit 134.

  Here, the decoding unit 110 performs a process of expanding (decompressing) the color data compressed by a compression method such as JPEG or MPEG.

  For example, data compression can be realized as follows.

  That is, first, data is divided into a plurality of macroblocks. Then, DCT (discrete cosine transform, orthogonal transformation including Hadamard transform, eigenvalue transform, etc. in a broad sense) is applied to each divided block. Thereby, the data is decomposed in frequency (spatial frequency). Next, each DCT coefficient (orthogonal transform coefficient in a broad sense) obtained by DCT is quantized. Then, Huffman coding (entropy coding, variable length coding) is performed, whereby compressed data is obtained.

  On the other hand, data decompression can be realized as follows.

  That is, first, compressed data is read from the information storage medium 180. Alternatively, the compressed data is read from the outside via the network (transmission line, communication line) and communication unit 196. The decoding unit 110 performs Huffman decoding (entropy decoding, variable length decoding) on the read compressed data. Next, the decoding unit 110 performs inverse quantization on the data after Huffman decoding. Then, inverse DCT is performed, whereby decompressed data is obtained.

  In the case of MPEG (MPEG2, MPEG4, etc.), for example, predictive encoding and predictive decoding (prediction between motion compensation frames) using temporal correlation may be performed.

  In this embodiment, compressed data (bit stream) generated by compressing color data (for example, RGB) included in the original image data is decompressed (decompressed) using the decoding unit 110 to obtain color data. Furthermore, in this embodiment, the compressed data (bitstream) generated by setting and compressing the alpha value (first data different from the color data in a broad sense) included in the original image data as color data, The data is decompressed by using the data decoding unit 110, and the obtained decompressed data is set as an α value (first data). In this way, the α value (first data) different from the color data can also be stored in the information storage medium 180 in a compressed state or read from the outside via the network and the communication unit 196. Will be able to.

  The decompressed data processing unit 120 performs various processes on the decompressed data obtained by the decoding unit 110.

  For example, the decompressed data processing unit 120 sets the data decompressed by the color data decoding unit 110 to the α value (first data) and passes it to the subsequent process. More specifically, the α value (first data) is set to a value corresponding to the gradation (gray scale) of the color component (red, green, or blue) included in the decompressed data. More specifically, the green component included in the decompressed data is set to the α value (first data).

  Note that noise may be superimposed on the expanded α value, and for example, the α value that should be in the range of 0 to 128 may be a value of 129 or more. In such a case, it is desirable to perform correction for clamping (clipping) the value of α to the upper limit value (given value).

  In the present embodiment, the compressed data is generated by compressing after the size of at least one of the horizontal direction and the vertical direction is reduced. The decompressed data processing unit 120 enlarges at least one of the decompressed data obtained by the decoding unit 110 in the horizontal direction and the vertical direction (size in the drawing buffer 174), and performs processing to restore the original size.

  The hit check unit 122 performs hit check processing between objects.

  Taking a game in which an object such as a character or a car moves on the map as an example, the hit check unit 122 determines whether or not the moving character or car collides with an obstacle (wall, building, etc.) on the map. Judgment is made so that characters and cars do not enter obstacles.

  Further, in the case of a shooting game in which a player hits a shot (bullet) aiming at a target character or a fighting game in which a character hits a kick or a punch, the hit check unit 122 uses the shot, kick or punch as a character. It is determined whether or not it hits. When a hit occurs, the amount of damage caused by the hit is calculated, and processing such as reducing the character's physical strength parameter or extinguishing the character is performed.

  In this embodiment, the data used for such a hit check is also compressed as color data, and is expanded using the color data decoding unit 110 during game processing.

  The movement control unit 124 performs processing for controlling the movement of an object (moving body) that moves on the map. That is, the acceleration and speed of the object in each frame are obtained based on the operation data input by the player using the operation unit 160, the terrain data of the map, etc., and the position and rotation angle (direction) of the object in each frame are obtained. . For example, when hit check data or movement control data is set on the map, the value of hit check data or movement control data at each position of the object is obtained, and the obtained data The process of controlling the movement of the object is performed based on the value of.

  In the present embodiment, such hit check data and movement control data are also compressed as color data and decompressed using the color data decoding unit 110 during game processing.

  The image control unit 126 performs processing for controlling an image of an object (moving body) that moves on the map. That is, the object image (color, brightness, α value, texture, etc.) is changed according to the position of the object on the map. For example, when the image control data of the object is set on the map, the value of the image control data at each position of the object is obtained, and the image of the object is controlled based on the obtained data value I do.

  In this embodiment, the image control data of such an object is also compressed as color data, and is expanded using the color data decoding unit 110 during game processing.

  The texture mapping unit 130 performs processing for mapping the texture stored in the texture storage unit 176 to the object. In this case, the texture mapping unit 130 can perform texture mapping using an index color / texture mapping LUT (lookup table) stored in the LUT storage unit 178.

  The hidden surface erasure unit 132 realizes hidden surface erasure processing by the following method, for example.

  That is, the second depth value of the moving object is obtained by a given routine (algorithm). Then, the obtained second depth value of the moving object (depth value for interrupting the moving object between other objects) and the other object (two-dimensional object, display object expressed so as to look three-dimensionally) The hidden surface of the moving object is deleted based on the first depth value of the primitive surface on which the two-dimensional image is drawn.

  In this case, the second depth value of the moving object includes, for example, the position of the moving object (the position of the representative point set at the bottom of the moving object) and the lower boundary line (lower boundary line of the other object). It is desirable to determine based on an extended boundary line extended by a given distance. Further, the second depth value may be obtained in consideration of the direction of the moving object and the movement history (movement path, movement order).

  The hidden surface removal performed by the hidden surface removal unit 132 is, for example, a depth in which objects (two-dimensional objects, primitive surfaces) are sorted according to depth values (drawing priority values), and objects are drawn in order from the back as viewed from the viewpoint. A depth comparison method (for example, a Z buffer method using a Z buffer 179) may be realized by a sorting method (Z sort method), or by comparing depth values for each pixel and drawing a pixel on the near side as viewed from the viewpoint. ).

  The α synthesis unit 134 performs α synthesis processing (α blending, α addition, α subtraction, or the like) using the α value. The α value (A value) is data stored in association with each pixel, for example, plus alpha data other than color data (RGB). The α value can be used as translucency (equivalent to transparency or opacity), mask data, bump data, and the like.

  Note that the game system of the present embodiment may be a system dedicated to the single player mode in which only one player can play, and not only such a single player mode but also a multiplayer mode in which a plurality of players can play. A system may be provided.

  Further, when a plurality of players play, game images and game sounds to be provided to the plurality of players may be generated using one terminal, or connected via a network (transmission line, communication line) or the like. Alternatively, it may be generated using a plurality of terminals (game machine, mobile phone).

2. Features of the present embodiment Next, features of the present embodiment will be described with reference to the drawings.

  Note that the first data of the present invention is not limited to the α value, but in order to simplify the description, the following description will be given mainly taking the case where the first data is the α value as an example.

2.1 Structure of Image Data FIG. 2 shows an example of a game image generated by this embodiment.

  This game image is composed of pictures of three parts as shown by F1, F2, and F3 in FIG. F1 is a background picture, F2 is a picture of a tree (a tree that crosses from the top to the bottom on the left side of FIG. 2), and F3 is a picture of a character (character).

  The image data of the tree picture shown in F2 of FIG. 3 is composed of color data (RGB) as shown in G1 of FIG. 4 and data of α value as shown in G2. The image data of the character picture indicated by F3 in FIG. 3 is composed of color data as indicated by G3 in FIG. 4 and α value data as indicated by G4.

  More specifically, the F2 tree picture in FIG. 3 maps a texture having G1 color data and G2 α value in FIG. 4 as texel data to, for example, a plate-like polygon (primitive surface in a broad sense). It is expressed by doing. Similarly, the picture of the character F3 in FIG. 3 is expressed by mapping a texture having the G3 color data and the G4 α value in FIG. 4 as texel data onto, for example, a plate-like polygon (primitive surface). ing.

  As shown in G2 and G4 of FIG. 4, the α value is set to be transparent in the outer area of the tree or character outline, and the α value is made opaque or translucent in the inner area of the tree or character outline. Is set. Thereby, a picture of a tree or character as shown in F2 and F3 of FIG. 3 can be expressed. Further, for example, by gradually changing the α value near the outline of a tree or character from transparent to opaque, anti-aliasing that blurs the outline of the tree or character can be realized, and the occurrence of jaggies or the like can be reduced.

2.2 Compression of α Value Some home game systems, for example, include a decoding unit for MPEG and JPEG as dedicated hardware in order to efficiently decompress compressed data.

  However, the decoding unit included in this type of game system generally targets only color data (RGB) and does not target data other than color data such as α values as the extension process. . The reason is as follows.

  In other words, the decoding unit included in this type of game system is usually provided to expand the data of a CG movie (CG image) displayed at the opening, interlude, and ending of the game. Such CG movie data is data after rendering processing such as α composition has already been completed (so-called solid picture data), and is only color data (RGB) that does not include α values. ing. Therefore, it is sufficient for the decoding unit to be able to expand only the color data, and the decoding unit is not configured to be able to expand data other than the color data such as the α value.

  In addition, since the MPEG and JPEG methods generally use color data as a target for compression and expansion processing, the decoding unit that expands data using these MPEG and JPEG methods also includes only color data as a target for expansion processing. It is supposed to be.

  As described above, since the decoding unit included in this type of game system targets only color data for expansion processing, data such as α values as indicated by G2 and G4 in FIG. 4 cannot be expanded. Therefore, the α value cannot be compressed and stored in an information storage medium or the like, and there is a problem that the used storage capacity of data cannot be saved.

  In order to solve such a problem, the following method is adopted in this embodiment.

  In other words, the first data (alpha value, hit check data, object movement control data, object image control data or depth value data, etc.) different from the color data is set as color data and compressed. The generated compressed data is read from, for example, an information storage medium or a network. Then, the read compressed data is decompressed using the decoding unit, and the obtained decompressed data is reset to the first data. Then, various processes for generating an image (α synthesis, hit check, object movement control, object image control process, etc.) are performed using the set first data.

  More specifically, as shown in FIG. 5, the compressed data CP1 (bit stream) generated by compressing the color data included in the original image data by the encoding unit, and the α value (in a broad sense, included) in the original image data. Prepared is compressed data CP2 generated by setting the first data) as color data and compressing it by the encoding unit.

  Then, color data is obtained based on the data EX1 obtained by decompressing the compressed data CP1 by the decoding unit. Further, the α value is obtained by setting the data EX2 obtained by decompressing the compressed data CP2 by the decoding unit to the α value. Then, an α composition process is performed using the obtained color data and the α value, thereby generating a game image as shown in FIG.

  In this way, the α value (first data) that is not subject to the decompression process of the decoding unit can be compressed and stored in the information storage medium. Accordingly, it is possible to save the data use storage capacity, and it is possible to generate a higher quality image with a small data use storage capacity.

2.3 α Value Setting Method In this embodiment, the α value (first data) is set to a value corresponding to the gradation (grayscale) of the color component included in the decompressed data obtained by the decoding unit. Or the green component included in the decompressed data is set to an α value (first data).

  For example, it is assumed that the α value to be compressed is data in the range of 0 to 255 as indicated by H1 in FIG. In this case, for example, as indicated by H2 in FIG. 6, when α = 0, R = G = B = 0, when α = 1, R = G = B = 1, and when α = 2. When R = G = B = 2,..., Α = 255, the α value is set to color data (RGB) of gradation corresponding to each value, such as R = G = B = 255. And compress it. The α value and the R, G, and B values need not be the same value. For example, when α = 128, R = G = B = 255 may be set.

  When decompressed data as shown in H3 of FIG. 6 is obtained by decompressing the compressed data in this way, for example, a value corresponding to the gradation of the color component included in the decompressed data as shown in H4 Set the α value to. More specifically, as shown in H5, for example, when G = 0, α = 0, when G = 1, α = 1, when G = 2, α = 2,... When G = 255, the green (G) component included in the decompressed data is set to an α value such that α = 255.

  That is, in a compression method such as MPEG or JPEG, the RGB representation is converted into a YCrCb (YUV) representation, and the luminance component Y, the color difference component Cr (color difference between R and Y), the color difference component, and Cb (color difference between B and Y) are separated. Is compressed. The human eye is sensitive to changes in luminance but not so sensitive to changes in color difference. Therefore, in MPEG and JPEG, compression is performed so that the code amount of the luminance component Y is larger than that of the color difference components Cr and Cb. An example of the conversion formula from RGB representation to YCrCb representation can be expressed as the following formula (1).

Y = 0.299 × R + 0.587 × G + 0.115 × B
Cr = 0.500 × R−0.418 × G−0.082 × B (1)
Cb = −0.169 × R−0.331 × G + 0.500 × B
As apparent from the above equation (1), the G (green) component has the largest contribution to the luminance component Y. Therefore, a large amount of code when the luminance component Y is compressed means that the information of the G component is least deteriorated.

  Therefore, as shown at H5 in FIG. 6, if the G component of the decompressed data is set to the α value, it becomes possible to minimize the information deterioration of the α value due to compression / expansion, and the higher the A quality image can be generated.

2.4 Scaling of size in the horizontal and vertical directions Now, data other than color data such as α value does not require highly accurate information required for color data. Therefore, in this embodiment, paying attention to this point, the following method is adopted.

  That is, as shown in FIG. 7, by reducing the size of the α value in the horizontal direction and vertical direction (either horizontal or vertical size, or both sizes may be used) and then compressing in the encoding unit, The compressed data CP2 for the α value is generated in advance.

  Then, after the compressed data CP2 is decompressed by the decoding unit, the size of the obtained decompressed data EX2 in the horizontal and vertical directions (either horizontal or vertical size or both sizes may be expanded). To restore the original size.

  In this way, although the information deterioration of the α value accompanying compression / expansion increases, the data amount of the compressed data CP2 can be greatly reduced. For example, when both the horizontal and vertical reduction ratios are halved, the amount of compressed data can be ¼.

  And even if the information of the α value deteriorates, the quality of the generated image does not deteriorate so much unlike the case where the information of the color data deteriorates. Therefore, if the method shown in FIG. 7 is adopted, it is possible to obtain the advantage that the used storage capacity of the data can be saved without significantly degrading the image quality.

2.5 Compression / Expansion of Hit Check, Movement Control, and Image Control Data In the above description, the case where the first data to be compressed / expanded as color data is an α value has been described as an example. As the first data, various data such as hit check data, object movement control data, object image control data, or a depth value (Z value) can be considered.

2.5.1 Hit Check Data For example, as shown in FIG. 8A, when the moving object 20 moves on the map, obstacles 22, 24, and 26 such as walls and buildings (entry prohibited area) And the moving object 20 need to be hit checked.

  In such a case, the data for specifying the position and shape of the obstacle, which is hit check data, is compressed as color data by the method shown in FIG. 5 and the like, and a decoding unit is used during game processing. To decompress and set the decompressed data as hit check data. Then, the value of hit check data at each position of the moving object 20 is obtained, and hit check processing (movement control processing in a broad sense) between the moving object 20 and the obstacles 22, 24, 26 is performed based on the obtained value. Do. In this way, it is possible to realize an appropriate hit check process between the moving object 20 and the obstacles 22, 24, and 26 while saving the use storage capacity of the data.

  In a shooting game or a fighting game, it is necessary to determine whether or not a shot (bullet), kick, or punch hits the character, and calculate the amount of damage to the character. In this case, as shown in FIG. 8B, the amount of damage is different for each part of the character 30. For example, when a shot hits the head, the amount of damage is increased and the hand or foot is hit. Reduce the amount of damage.

  In such a case, the data of the amount of damage at each part, which is hit check data, is compressed as color data by the method shown in FIG. 5 and the like, decompressed using a decoding unit during game processing, and decompressed. Set the data as hit check data again. In this way, it is possible to realize an appropriate and realistic hit check process between the character 30 and a shot or the like while saving the data storage capacity used.

2.5.2 Movement Control Data When the moving object 20 moves on the map as shown in FIG. 8C, movement control corresponding to the area to which the moving object 20 moves is applied to the moving object 20. It is desirable to apply. For example, when the moving object 20 enters the swamp 32 (speed change region), the speed of the moving object 20 is decreased.

  In such a case, the movement control data of the moving object 20 is compressed as color data by the method shown in FIG. 5 and the like, decompressed using a decoding unit during game processing, and the decompressed data is used as movement control data. Try to set again. And the value of the data for movement control in each position of the moving object 20 is calculated | required, and the movement control process of the moving object 20 is performed based on the calculated | required value. In this way, realistic movement control of the moving object 20 can be realized while saving the use storage capacity of data.

  Note that various data for controlling the position, speed, acceleration, direction, or the like of the moving object can be considered as the movement control data of the moving object.

2.5.3 Image Control Data In FIG. 9A, it is assumed that the light source vector LC is oriented in the direction E1, and the shadow area 40 (shading calculation change area) of the tree 42 is assumed to follow this assumption. ) Is set on the map. When it is determined that the moving object 20 has entered the shadow area 40, the shading calculation for the moving object 20 is changed so that the shading of the moving object 20 becomes dark overall. In this way, whether or not to change the shading of the moving object 20 can be determined only by determining whether or not the position of the moving object 20 is within the shadow area 40. Therefore, the processing load can be remarkably reduced as compared with the method of determining whether to change the shading of the moving object 20 based on the three-dimensional solid data.

  In such a case, data for specifying the position and shape of the shadow area 40, which is image control data for the moving object, is compressed as color data by the method shown in FIG. The decoding unit is used for decompression, and the decompressed data is reset as image control data for the moving object 20. Then, the value of the image control data at each position of the moving object 20 is obtained, and the image control process of the moving object 20 is performed based on the obtained value. In this way, real shading processing of the moving object 20 can be realized with a small storage capacity of data.

  In order to realize a more realistic expression, it is desirable to set a shading calculation parameter for the shadow area 40 (shading calculation change area). For example, as shown in FIG. 9B, luminance parameters I0, I1, I2, and I3, which are one of shading calculation parameters, are set for the vertices VE0, VE1, VE2, and VE3 of the shadow region 40, respectively. Then, based on the luminance parameters I0 to I3, a luminance parameter used for the shading calculation of the moving object 20 is obtained, and the shading calculation for the moving object 20 is performed based on the obtained luminance parameter. In this way, as shown in FIG. 9B, the shading applied to the moving object 20 can be changed in various places in the shadow area 40, and more realistic shading expression can be achieved. Is possible.

  In this case, it is desirable to compress and expand the shading calculation parameter (luminance parameter) as image control data for the moving object.

  Note that various data for controlling the color, brightness, α value, texture, etc. of the moving object can be considered as the image control data of the moving object.

2.5.4 Depth Value Now, in the game system, what is called a movie (moving image) is played in order to increase the player's willingness to motivate the game and increase the player's excitement at the opening, the intermission, and the ending of the game. There are many cases. In this movie, the video and live-action video produced by the CG tool are played back, so that it is more realistic and realistic than images generated by moving 3D objects composed of polygons (primitive surfaces) in real time. Expression is possible.

  However, in conventional game systems, movie data that is data for movie playback includes only color data (RGB). Therefore, for example, when an image in which a moving object such as a movie and a character is combined is generated, the character is always displayed in front of the movie, and there is a problem that an image lacking realism is generated.

  Therefore, in order to solve such a problem, in the present embodiment, the depth value Z1 is included in movie data that is data for movie playback. Then, an image in which the movie and the character are combined is generated while performing hidden surface removal based on the depth value Z1 and the depth value Z2 of the character (moving object in a broad sense).

  More specifically, for example, as shown in FIG. 10, the data of the depth value Z1 is included in addition to the color data (RGB) for each pixel of each frame image constituting the movie. Then, Z1 is compared with the depth value Z2 of the character, and hidden surface removal is performed according to an algorithm such as a Z buffer method to generate an image in which the movie and the character are combined.

  In this way, as shown in FIG. 11A, the character 30 can be interrupted in the movie picture. That is, it is possible to perform image representation such as the character 30 hiding behind the chiffon 50 (display object) expressed in a movie or the character going out from an entrance 52 expressed in a movie. Alternatively, it is possible to display an image such as the character 30 looking into the window 54 from the other side of the window 54.

  That is, in the previous movies, the movie data includes only color data and does not include depth value data. Therefore, when a composite image of a movie and a character is to be generated, the character 30 is always displayed in front as shown in FIG. 11B, and the real image cannot be generated.

  According to the present embodiment, as shown in FIG. 11A, the character 30 may or may not be hidden behind the display object in the movie in accordance with the depth value Z2 of the character 30. Therefore, a more realistic and realistic image can be generated.

  In this embodiment, the depth value Z1 as shown in FIG. 10 is compressed as color data by the method shown in FIG. 5 and the like, decompressed using a decoding unit during game processing, and the decompressed data is used as the depth value Z1. Try to set again. In this way, not only the color data constituting the movie but also the depth value Z1 can be compressed and stored in the information storage medium. Therefore, it is possible to generate a realistic image in which the character is hidden behind the display object in the movie while saving the storage capacity of the data.

  Note that the depth value to be compressed / expanded in this embodiment is particularly preferably a depth value associated with a movie as shown in FIG. 10, but is not limited to this.

  In addition, the movie in the present embodiment may be a CG video composed of a series of cell images produced by a CG tool, or a live-action video shot by a camera.

  When a CG video is used as a movie, the depth value data of each pixel generated when the CG is created is included in the movie data without being discarded. That is, the final depth value data stored in the Z buffer of the CG tool is normally discarded, but is not discarded, but is included in the movie data together with the color data (RGB). . In this way, movie data including depth value data can be prepared without much effort.

  Further, the depth value may be set for all the frame images, or may be set only for a part of the frame images. Further, the depth value may be set for all the pixels of the frame image constituting the movie, or may be set only for some pixels.

  Further, the movie may be used as a background as shown in FIG. 11A, or may be used to represent an enemy boss (moving object) or the like. In this case, for example, a virtual screen for movie display is prepared, and an enemy boss movie is projected onto the virtual screen. Alternatively, a polygon (primitive surface) for movie display may be prepared, and the movie may be mapped to the polygon as a texture.

2.6 Utilization of Index Color Texture Mapping The process of setting the decompressed data EX2 of the compressed data CP2 in FIG. 5 to the first data such as the α value is realized by a technique using index color / texture mapping, for example. be able to.

  In the index color texture mapping, in order to save the used storage capacity of the texture storage unit, the index number is stored in association with each texel of the texture instead of the actual color data (RGB) as shown by A1 in FIG. The Further, as indicated by A2 in FIG. 12, color data designated by an index number and an α value are stored in a lookup table LUT (color palette) for index color / texture mapping. When texture mapping is performed on an object, the LUT is referred to based on the index number of each texture texel, the corresponding color data or α value is read from the LUT, and the read color data and α value are read out. Based on the above, the image is drawn in the frame buffer.

  In such texture mapping in the index color mode, the number of colors that can be used is reduced (for example, 16 colors) compared to texture mapping in the normal mode that does not use the LUT. However, since it is not necessary to store actual color data (for example, 16 bits) in the texture storage unit, the used storage capacity of the texture storage unit can be greatly saved.

  In the present embodiment, such index color / texture mapping is used in a form different from a normal one.

  That is, first, as shown by B1 in FIG. 13, the color data of each pixel of the G plane (which may be other color components) included in the decompressed data is set as the index number of the lookup table LUT (it is regarded as the index number). . Then, as shown in B2, index color / texture mapping is performed on the virtual object using the LUT in which the color data of the G plane of the decompressed data is set as the index number, and the color data of the G plane is converted to an α value (αOUT ) And draw in a frame buffer or the like. In this way, the color data of the G plane can be converted into an α value in one batch by, for example, texture mapping, and the processing efficiency can be improved.

  Moreover, the index color / texture mapping is executed at high speed by a drawing processor (drawing unit) which is dedicated hardware included in this type of game system. Therefore, the processing for setting (converting) the color data of the G plane to the α value can be accelerated.

  In FIG. 13, the α value setting process is realized by texture mapping to a polygon (virtual object) having a display screen size. However, the texture mapping is performed to a polygon having a block size obtained by dividing the display screen. Also good.

  That is, as shown in C1 of FIG. 14, the frame buffer (display screen) is divided into a plurality of blocks, and as shown in C2, the color data of each block is texture-mapped into polygons of the divided block size using the LUT. To do.

  In this way, for example, when the texture-mapped polygon is temporarily drawn in the work buffer (separate buffer), the occupation area of the work buffer on the VRAM can be reduced.

  That is, when texture mapping is performed on a polygon having a display screen size as shown in FIG. 13, a work buffer having a display screen size must be secured on the VRAM in order to temporarily draw the polygon having the display screen size. There is a risk of hindering the processing.

  As shown in FIG. 14, if texture mapping is performed on polygons having a divided block size, a work buffer having a divided block size may be prepared on the VRAM, so that the area occupied by the work buffer can be reduced. Therefore, it is possible to effectively use limited hardware resources.

3. Process of this embodiment Next, a detailed example of the process of this embodiment will be described with reference to the flowcharts of FIGS. 15 and 16.

  FIG. 15 is a flowchart of processing during compression.

  First, as shown in FIG. 17, based on the original image data IOR with α, image data IC composed of RGB planes (color data) of IOR, and image data in which the RGB plane is replaced with the α plane of the original image data IOR. Iα (R = G = B = α) is created (step S1).

  Next, when the reduction ratios in the horizontal (width) direction and the vertical (height) direction are SX and SY (0.0 <SX <1.0, 0.0 <SY <1.0), step S1 The image data Iα obtained in the above is reduced to SX and SY times in the horizontal and vertical directions to generate image data IαR (step S2).

  Then, each of the image data IC obtained in step S1 and the image data IαR obtained in step S2 is compressed by MPEG, JPEG method or the like to generate bit streams BC and BαR (step S3). Then, the bit streams BC and BαR generated in this way are written in an information storage medium in which a game program, game data, and the like are stored (may be distributed via a network).

  FIG. 16 is a flowchart of processing during decompression.

  First, as shown in FIG. 18, the bit streams BC and BαR obtained in step S3 of FIG. 15 are expanded (developd) to obtain image data IC ′ and IαR ′ (step S11).

  Next, assuming that the reduction ratios in the horizontal and vertical directions in the scaling performed in step S2 in FIG. 15 are SX and SY, the image data IαR ′ is 1.0 / SX times in the horizontal and vertical directions. The image data Iα ′ is generated by enlarging the image by 0.0 / SY (step S12).

  Then, the G (green) plane of the image data Iα ′ obtained in step S12 is set as an α plane, and image data IOR ′ with α is obtained from the α plane and the RGB plane of the image data IC ′ (step S12). S13). Then, α composition processing or the like is performed based on the image data IOR ′, and a game image as shown in FIG. 2 is generated.

4). Hardware Configuration Next, an example of a hardware configuration capable of realizing the present embodiment will be described with reference to FIG.

  The main processor 900 operates based on a program stored in the CD 982 (information storage medium), a program transferred via the communication interface 990, or a program stored in the ROM 950 (one of information storage media). Various processes such as processing, image processing, and sound processing are executed.

  The coprocessor 902 assists the processing of the main processor 900, has a product-sum calculator and a divider capable of high-speed parallel calculation, and executes matrix calculation (vector calculation) at high speed. For example, if a physical simulation for moving or moving an object requires processing such as matrix operation, a program operating on the main processor 900 instructs (requests) the processing to the coprocessor 902. )

  The geometry processor 904 performs geometry processing such as coordinate transformation, perspective transformation, light source calculation, and curved surface generation, has a product-sum calculator and a divider capable of high-speed parallel computation, and performs matrix computation (vector computation). Run fast. For example, when processing such as coordinate transformation, perspective transformation, and light source calculation is performed, a program operating on the main processor 900 instructs the geometry processor 904 to perform the processing.

  The data decompression processor 906 performs a decoding process for decompressing the compressed image data and sound data, and a process for accelerating the decoding process of the main processor 900. As a result, a moving image compressed by the MPEG method or the like can be displayed on the opening screen, the intermission screen, the ending screen, or the game screen. Note that the image data and sound data to be decoded are stored in the ROM 950 and the CD 982 or transferred from the outside via the communication interface 990.

  The drawing processor 910 performs drawing (rendering) processing of an object composed of primitive surfaces such as polygons and curved surfaces at high speed. When drawing an object, the main processor 900 uses the function of the DMA controller 970 to pass the object data to the drawing processor 910 and transfer the texture to the texture storage unit 924 if necessary. Then, the rendering processor 910 renders the object in the frame buffer 922 at high speed while performing hidden surface removal using a Z buffer or the like based on the object data and texture. The drawing processor 910 can also perform α blending (translucent processing), depth cueing, mip mapping, fog processing, bilinear filtering, trilinear filtering, anti-aliasing, shading processing, and the like. When an image for one frame is written in the frame buffer 922, the image is displayed on the display 912.

  The sound processor 930 includes a multi-channel ADPCM sound source and the like, and generates high-quality game sounds such as BGM, sound effects, and sounds. The generated game sound is output from the speaker 932.

  Operation data from the game controller 942, save data from the memory card 944, and personal data are transferred via the serial interface 940.

  The ROM 950 stores system programs and the like. In the case of an arcade game system, the ROM 950 functions as an information storage medium, and various programs are stored in the ROM 950. A hard disk may be used instead of the ROM 950.

  The RAM 960 is used as a work area for various processors.

  The DMA controller 970 controls DMA transfer between the processor and memory (RAM, VRAM, ROM, etc.).

  The CD drive 980 drives a CD 982 (information storage medium) in which programs, image data, sound data, and the like are stored, and enables access to these programs and data.

  The communication interface 990 is an interface for transferring data to and from the outside via a network. In this case, as a network connected to the communication interface 990, a communication line (analog telephone line, ISDN), a high-speed serial bus, or the like can be considered. By using a communication line, data transfer via the Internet becomes possible. Further, by using the high-speed serial bus, data transfer with other game systems becomes possible.

  All of the means of the present invention may be realized (executed) only by hardware, or only by a program stored in an information storage medium or a program distributed via a communication interface. Also good. Alternatively, it may be realized by both hardware and a program.

  When each means of the present invention is realized by both hardware and a program, the information storage medium stores a program for realizing each means of the present invention using hardware. Become. More specifically, the program instructs each processor 902, 904, 906, 910, 930, etc., which is hardware, and passes data if necessary. Each of the processors 902, 904, 906, 910, 930 and the like implements each unit of the present invention based on the instruction and the passed data.

  FIG. 20A shows an example in which the present embodiment is applied to an arcade game system. The player enjoys the game by operating the lever 1102, the button 1104, and the like while viewing the game image displayed on the display 1100. Various processors and various memories are mounted on the built-in system board (circuit board) 1106. A program (data) for realizing each means of the present invention is stored in a memory 1108 which is an information storage medium on the system board 1106. Hereinafter, this program is referred to as a storage program (storage information).

  FIG. 20B shows an example in which the present embodiment is applied to a home game system. The player enjoys the game by operating the game controllers 1202 and 1204 while viewing the game image displayed on the display 1200. In this case, the stored program (stored information) is stored in a CD 1206, which is an information storage medium that can be attached to and detached from the main system, or memory cards 1208, 1209, and the like.

  FIG. 20C shows a host device 1300 and terminals 1304-1 to 1304-n connected to the host device 1300 via a network 1302 (a small-scale network such as a LAN or a wide area network such as the Internet). An example in which the present embodiment is applied to a system including (game machine, mobile phone) is shown. In this case, the storage program (storage information) is stored in an information storage medium 1306 such as a magnetic disk device, a magnetic tape device, or a memory that can be controlled by the host device 1300, for example. When the terminals 1304-1 to 1304-n can generate game images and game sounds stand-alone, the host device 1300 receives a game program and the like for generating game images and game sounds from the terminal 1304-. 1 to 1304-n. On the other hand, if it cannot be generated stand-alone, the host device 1300 generates a game image and a game sound, which is transmitted to the terminals 1304-1 to 1304-n and output at the terminal.

  In the case of the configuration of FIG. 20C, each means of the present invention may be realized by being distributed between the host device (server) and the terminal. Further, the above storage program (storage information) for realizing each means of the present invention may be distributed and stored in the information storage medium of the host device (server) and the information storage medium of the terminal.

  The terminal connected to the network may be a home game system or an arcade game system. When the arcade game system is connected to a network, the save information storage device can exchange information with the arcade game system and exchange information with the home game system. It is desirable to use (memory card, portable game device).

  The present invention is not limited to that described in the above embodiment, and various modifications can be made.

  For example, the first data to be subjected to the compression or decompression processing of the present invention is particularly preferably data as described in the present embodiment, but is not limited to this, for example, pixels (including texels). Various data set in association with can be targeted.

  The process of setting the decompressed data as the first data may be realized by using index color / texture mapping, or the data (for example, G component color data) of each pixel (texel) of the decompressed data. You may implement | achieve by the software process set to 1st data (for example, alpha value in the said pixel) one by one.

  The present invention can also be applied to compression / decompression of the α value (first data in a broad sense) of a movie texture in which the captured moving image is directly mapped to an object.

  In addition, the decoding unit of the present invention may be realized by hardware or software.

  In the invention according to the dependent claims of the present invention, a part of the constituent features of the dependent claims can be omitted. Moreover, the principal part of the invention according to one independent claim of the present invention can be made dependent on another independent claim.

  The present invention can also be applied to various games (such as fighting games, shooting games, robot battle games, sports games, competitive games, role playing games, music playing games, dance games, etc.).

  The present invention is also applicable to various game systems (image generation systems) such as a commercial game system, a home game system, a large attraction system in which a large number of players participate, a simulator, a multimedia terminal, and a system board for generating game images. Applicable.

20 Moving objects 22, 24, 26 Obstacles (prohibition area)
30 character 32 swamp (speed change area)
40 Shadow area (shading calculation change area)
DESCRIPTION OF SYMBOLS 100 Processing part 110 Decoding (decompression) part 120 Decompression data processing part 122 Hit check part 124 Movement control part 126 Image control part 130 Texture mapping part 132 Hidden surface deletion part 134 Alpha composition part 160 Operation part 170 Storage part 172 Main memory part 174 Drawing Buffer 176 Texture storage unit 178 LUT storage unit 179 Z buffer 180 Information storage medium 190 Display unit 192 Sound output unit 194 Portable information storage device 196 Communication unit

Claims (8)

A game system having a decoding means for decompressing compressed color data,
Decompressed data in which compressed data generated by setting and compressing first data different from color data as color data is decompressed using the decoding means, and the obtained decompressed data is set as first data Processing means;
Means for performing a given process for generating an image using the set first data,
The game system, wherein the first data is a depth value. In claim 1,
The means for performing the given process is:
A game system that performs hidden surface removal based on a set depth value. In claim 2,
The decompressed data processing means is
The compressed data generated by setting and compressing the depth value included in the movie data as color data is expanded using the decoding means, and the obtained expanded data is set as the depth value.
The means for performing the given process is:
A game system characterized by performing hidden surface removal based on a set depth value and a depth value of a moving object, and generating an image in which the movie and the moving object are combined. A computer-readable information storage medium,
The compressed data generated by setting the first data different from the color data to the color data and compressing the data is decompressed using the decoding means for decompressing the compressed color data, and the obtained decompressed data is the first data. Decompression data processing means to set to the data of,
A program for causing a computer to function as a means for performing a given process for generating an image using the set first data is stored.
The information storage medium, wherein the first data is depth value data. In claim 4,
The means for performing the given process is:
An information storage medium characterized by performing hidden surface removal based on a set depth value. In claim 5,
The decompressed data processing means is
The compressed data generated by setting and compressing the depth value included in the movie data as color data is expanded using the decoding means, and the obtained expanded data is set as the depth value.
The means for performing the given process is:
An information storage medium characterized by performing hidden surface removal based on a set depth value and a depth value of a moving object, and generating an image in which the movie and the moving object are combined. A method for generating compressed data used in a game system having a decoding means for decompressing compressed color data,
The first data different from the color data to be decompressed by the decoding means is set as color data and compressed to generate compressed data used in the game system,
The compressed data generation method, wherein the first data is depth value data. In claim 7,
A compressed data generation method comprising: generating compressed data used in a game system by setting a depth value included in movie data to color data and compressing the color data.

Images