Abstract:
In order to represent, as a video, changes in the light-and-shade patterns of an image with a reduced demand for storage capacity and a relatively small amount of preparation, light-and-shade pattern data representing the light-and-shade pattern to be added to an original image and constructed by assigning a palette number to each image region obtained by dividing the original image is prepared. A plurality of palette data constructed by assigning color information having brightness difference to each palette number are generated, the plurality of palette data being different from each other. A plurality of light-and-shade images each based on the light-and-shade pattern data and one of the palette data generated at the palette data generating step are translucently blended, in sequence, into the original image.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image processing device, image processing method, and information recording medium, and in particular, to technology for displaying an original image having light-and-shade pattern change with small processing load. 
     2. Description of the Related Art 
     When changes in the light-and-shade pattern of an image are represented in a video, such as, for example, a waving national flag or a moving water surface, a so-called animation method has been employed wherein a plurality of images each representing the course of change are pre-provided in a storage device and sequentially displayed. 
     However, pre-provision of a plurality of images requires a large storage capacity. 
     SUMMARY OF THE INVENTION 
     The present invention was conceived to solve the above-mentioned problem, and one object of the present invention is to provide an image processing device, an image processing method, and an information recording medium which can easily represent, by video, the changes in the light-and-shade pattern of an image and which lowers the necessary storage capacity. 
     In order to achieve at least the object mentioned above, according to one aspect of the present invention, there is provided an image processing device comprising: original image data obtaining means for obtaining original image data representing an original image; light-and-shade pattern data obtaining means for obtaining light-and-shade pattern data representing the light-and-shade pattern to be added to the original image and constructed by assigning a palette number to each image region obtained by dividing the original image; palette data generating means for generating a plurality of palette data each constructed by assigning color information to each palette number, said color information having different brightness from each other, the plurality of palette data being different from each other; translucent blending means for translucently blending, in sequence, a plurality of light-and-shade images each based on the light-and-shade pattern data and one of the palette data generated by the palette data generating means, into the original image based on the original image data; and image displaying means for sequentially displaying images obtained by the translucent synthesis. 
     According to another aspect of the present invention, there is provided an image processing method, comprising: an original image data obtaining step for obtaining original image data representing an original image; a light-and-shade pattern data obtaining step for obtaining light-and-shade pattern data representing the light-and-shade pattern to be added to the original image and constructed by assigning a palette number to each image region obtained by dividing the original image; a palette data generating step for generating a plurality of palette data each constructed by assigning color information to each palette number, said color information having different brightness from each other, the plurality of palette data being different from each other; a translucent blending step for translucently blending, in sequence, a plurality of light-and-shade images each based on the light-and-shade pattern data and one of the palette data generated at the palette data generating step, into the original image based on the original image data; and an image displaying step for sequentially displaying the images obtained by the translucent synthesis. 
     According to yet another aspect of the present invention, there is provided an information recording medium for storing a program which, when executed by a computer, causes the computer to perform the steps of: obtaining original image data representing an original image; obtaining light-and-shade pattern data representing the light-and-shade pattern to be added to the original image and constructed by causing a palette number to correspond to each image region obtained by dividing the original image; generating a plurality of palette data each constructed by assigning color information to each palette number, said color information having different brightness from each other, the plurality of palette data being different from each other; and translucently blending, in sequence, a plurality of light-and-shade images each based on the light-and-shade pattern data and one of the generated palette data, into the original image based on the original image data. 
     In the present invention, original image data and light-and-shade pattern data are obtained. The light-and-shade pattern data represents the light-and-shade pattern to be added to the original image, and is constructed by causing correspondence between a palette number and each image region obtained by dividing the original image. Moreover, in the present invention, a plurality of palette data are generated. The plurality of palette data may be generated at once or sequentially generated at each image display. The plurality of palette data are different from each other and are constructed by causing correspondence between each palette number and color information with brightness difference. A plurality of light-and-shade images each based on one of the palette data and the light-and-shade pattern data are translucently blended, in sequence, into the original image, and displayed. Because of this, images with light-and-shade pattern added to the original image are displayed, and the light-and-shade pattern changes. In this case, the original image data, light-and-shade pattern data, and palette data in general require less data than the data used in the animation method mentioned above. Thus, changes in light-and-shade pattern in an image can easily be represented as a video without significantly increasing the necessary storage capacity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a diagram showing an overall structure of a game device (image processing device) according to a preferred embodiment of the present invention. 
         FIG. 2  is a diagram showing an example of an original image. 
         FIG. 3  is a diagram showing an example of light-and-shade pattern. 
         FIG. 4  is a diagram showing a structure of palette data. 
         FIG. 5  is a diagram showing an example of an image with light-and-shade. 
         FIG. 6  is a flowchart for explaining the image processing for displaying an image with light-and-shade. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The entire disclosure of the corresponding Japanese application 2000-306610 filed on Oct. 5, 2000 including specification, claims, drawings and summary, is incorporated herein by reference. 
     The preferred embodiment of the present invention will now be described referring to the drawings. 
       FIG. 1  shows a structure of a game device according to a preferred embodiment of the present invention. A game device  10  shown in  FIG. 1  is a preferred embodiment of the image processing device according to the present invention, and at the same time, is for embodying the image processing method according to the present invention. A DVD-ROM  25  shown in  FIG. 1  is one preferred embodiment of the information recording medium according to the present invention. The game device  10  is constructed by connecting a monitor  18  and a speaker  22  to a consumer game machine  11  and attaching the DVD-ROM  25  which is the information recording medium. Here, the DVD-ROM  25  is used for supplying game program (which includes game data; it is assumed that the term “game program” includes game data hereinafter) to the consumer game machine  11 . However, any other information recording medium can be used, such as, for example, a CD-ROM, a ROM card or the like. It is also possible to connect a modem or a terminal adapter and to supply the game program to the consumer game machine  11  from a remote location, via a communication network such as the Internet. 
     The consumer game machine  11  includes a microprocessor  14 , an image processing section  16 , a main memory  26 , and an input/output processing section  30 , connected to each other by a bus  12  so that data communication between these components is possible. A controller  32 , an audio processing section  20 , and a DVD reproduction section  24  are connected to the input/output processing section  30 . Each of the components of the game machine  11  other than the controller  32  are stored in a housing. A consumer TV set, for example, is used as the monitor  18 , and the internal speaker of the TV set is used as the speaker  22 . 
     The microprocessor  14  controls each section of the consumer game machine  11  based on the operating system stored in a ROM (not shown) or based on a game program read out from the DVD-ROM  25 . The bus  12  is provided for the communication of address and data between each section of the consumer game machine  11 . The game program read out from the DVD-ROM  25  is written onto the main memory  26  as necessary. The image processing section  16  includes a VRAM. The image processing section  16  receives the image data transmitted from the microprocessor  14 , draws the game screen on the VRAM, and, at the same time, converts the image data into a video signal and outputs to the monitor  18  at a predetermined timing. 
     The input/output processing section  30  is an interface for relaying data communication between the controller  32 , audio processing section  20 , and DVD-ROM reproduction section  24 , and the microprocessor  14 . The controller  32  is input means for allowing a player to manipulate the game. The input/output processing section  30  scans the manipulation condition of various buttons on the controller  32  at a predetermined interval (for example, every 1/60 second), and transmits manipulation signals representing the scan result to the microprocessor  14  via the bus  12 . The microprocessor  14  judges the game manipulation by the player based on the manipulation signal. The audio processing section  20  includes a sound buffer, and replays data such as, for example, music and game sound effects read out from the DVD-ROM  25  and stored in the sound buffer, for output from the speaker  22 . The DVD reproduction section  24  reads out the game program stored in the DVD-ROM  25  in response to instructions from the microprocessor  14 . 
     A technique for displaying a national flag with light-and-shade pattern by the game device  10  having the above described structure will now be described. In this game device  10 , a light-and-shade image is translucently blended into the original image shown in  FIG. 2  (showing the national flag of Japan). The light-and-shade image is obtained by representing the light-and-shade pattern shown in  FIG. 3  using the palette data shown in  FIG. 4 . In this manner, an image of the national flag of Japan with light-and-shade, as shown in  FIG. 5  is displayed on the monitor  18 . 
     First, the original image shown in  FIG. 2  can be displayed based on the original image data (including pattern and color data, and palette data), and the original image data is pre-stored in the DVD-ROM  25  and loaded to the main memory  26  by the microprocessor as necessary. 
     The light-and-shade pattern shown in  FIG. 3  is a pattern represented by light-and-shade pattern data (pattern and color data), and has the same size as the original image. Nine substantially band-shaped image regions are assigned from the bottom left corner to the top right corner. Palette numbers are set so that the number is  0 ,  1 ,  2 ,  3 ,  2 ,  1 ,  0 ,  1 ,  2  from the bottom left to the top right, in that order. In other words, the light-and-shade pattern data is constructed by assigning a palette number to each of the image regions. Specifically, the palette numbers are assigned to each of the image regions so that the corresponding palette number is incremented by 1 from 0, from the bottom left corner of the image toward the top right corner until the palette number becomes  3 , at which point the palette number starts to decrease by 1. When a palette number of  0  is reached again, the assigned palette number again starts to increase by 1. The light-and-shade pattern data is also pre-stored in the DVD-ROM  25 , and is loaded to the main memory  26  by the microprocessor  14  as necessary. 
     The palette data shown in  FIG. 4  stores the palette number ( 0  to  3 ) and color information with one-to-one correspondence, and is used with the light-and-shade pattern data as described above as a pair. In the palette data shown in  FIG. 4 , color information of no-color and transparent is set to correspond to the palette number  0  and color information of gray and translucent are set to correspond to the palette numbers  1  through  3 . Here, the color information is set so that the gray becomes more concentrated as the palette number is incremented from  1  toward  3 . The palette data is also pre-stored in the DVD-ROM  25  and loaded to the main memory  26  by the microprocessor  14  as necessary. 
       FIG. 5  shows an image of the national flag of Japan with the light-and-shade, displayed on the monitor  18 . This image is obtained by transferring the image of the national flag of Japan shown in  FIG. 2  from the main memory  26  to the VRAM of the image processing section  16 , and then translucently blending the light-and-shade pattern shown in  FIG. 3  using the palette data shown in  FIG. 4  into the image in the VRAM. As shown in  FIG. 5 , the image of the national flag of Japan with the light-and-shade shows a point in time where a light-and-shade pattern is generated by a gradual change in brightness from the bottom left corner to the top right corner, compared to the image of the national flag of Japan shown in  FIG. 2 . 
     In the game device  10 , after the image of the national flag of Japan with the light-and-shade is displayed, the palette data shown in  FIG. 4  is modified, and the light-and-shade pattern shown in  FIG. 3  is translucently blended into the image of the national flag of Japan shown in  FIG. 2  using the modified palette data, and the blended image is then displayed. As a result of such a modification to the palette data, the correspondence of the palette number and the color information is shifted from the original configuration by 1. In other words, palette number  1  is set to color information of non-color and transparent, and palette numbers  2 ,  3 , and  0  are set to color information of gray and translucent, the gray color becoming more concentrated in that order. Moreover, after the image is displayed using the modified palette data, the palette data is further modified so that palette number  2  is set to color information of non-color and transparent, and palette numbers  3 ,  0 , and  1  are set to color information of gray and translucent, the gray color becoming more concentrated in that order. Similarly, after each image display using the modified palette data, the correspondence between the palette number and color information are shifted by 1 compared to the previous condition. After three such modifications to the palette data, the original palette data ( FIG. 4 ) is used again. By sequentially changing the palette data and translucently blending the light-and-shade pattern using such palette data onto the national flag of Japan as shown in  FIG. 2 , the national flag of Japan can be represented as the high brightness section and the low brightness section moving from the bottom left corner of the image to the top right corner. In this manner, the national flag of Japan waving in wind can be preferably represented as video. 
       FIG. 6  shows a flowchart for explaining the program to execute the above described image processing. The program shown in  FIG. 6  is stored in the DVD-ROM  25 , loaded to the main memory  26  as necessary, and executed by the microprocessor  14 . Tn this process, the original image data which represents the national flag of Japan as shown in  FIG. 2  is loaded from the DVD-ROM  25  to the main memory  26  and transferred to the VRAM of the image processing section  16 . In this manner, the original image is written to VRAM (frame memory) (step S 101 ). Then, the light-and-shade pattern data representing the light-and-shade pattern of  FIG. 3  and the palette data of  FIG. 4  are loaded from the DVD-ROM  25  to the main memory  26 . A light-and-shade image based on the palette data and the light-and-shade pattern data is translucently blended into the image of the national flag of Japan already drawn on the VRAM (step S 102 ). In this manner, an image of the national flag of Japan with the light-and-shade drawn on the VRAM is output to and displayed on the monitor  18  at a predetermined timing. Then, the microprocessor updates (modifies) the palette data loaded to the main memory  26  so that the correspondence between the palette number and the color information are shifted by 1, as described above (step S 103 ). The modified palette data is used when the light-and-shade image is again translucently blended to the original image (step S 102 ). In this manner, the national flag of Japan waving in wind can be represented as a video. 
     As described, in the game device  10 , the national flag of Japan waving in wind can be represented in an image by making data of the original image of the national flag of Japan (without light-and-shade pattern) shown in  FIG. 2  and of the light-and-shade pattern shown in  FIG. 3 , preparing palette data shown in  FIG. 4 , and storing these data in the DVD-ROM  25 . In other words, in a desired image, the changes in light-and-shade pattern can be represented by a lower storage capacity and requires less preparation compared to the prior art. 
     The present invention is not limited to the above mentioned embodiment. 
     For example, in the above explanation, a light-and-shade pattern is added to an image of a flag. However, it is possible to apply the present invention to any desired image to add a light-and-shade pattern. For example, an image of a wave generated on a water surface, or the like, can be represented in an image.