Graphic accelerator with interpolate function

• US 6,819,328 B1
• Filed: 10/02/2000
• Issued: 11/16/2004
• Est. Priority Date: 11/05/1999
• Status: Expired due to Fees

• Current Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Original Assignee: Mitsubishi Electric System (Mitsubishi Electric Corporation), Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Moriwaki, Shohei, Shimakawa, Kazuhiro, Azekawa, Yoshifumi, Chiba, Osamu
• Primary Examiner(s): Tung, Kee M.
• Application Number:
  US09/676,755
• Time in Patent Office: 1,506 Days
• Field of Search: 345/501-506, 345/519-520, 345/522, 345/530-574, 345/422, 345/589, 345/591, 345/592, 345/593, 345/600, 345/603-606
• US Class Current: 345/591
• CPC Class Codes: G06T 1/60 Memory management
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/391 Resolution modifying circuits, e.g. variable screen formats

Abstract

A graphic accelerator includes an image-forming data decode unit, an image memory control unit and a screen data generation unit. The image memory control unit performs a control for writing an output of the image-forming data decode unit to a frame buffer and reading out information stored in the frame buffer. Screen data generation unit restores (interpolates) the color information based on the data read out from the frame buffer and generates screen data. In the frame buffer the information for each pixel is stored in a deleted form including two types of color information among three types of color information consisting of R, G and B. At the reading, the deleted color information is interpolated with the color information of other pixel.

Claims

1. A graphic accelerator generating display data based on data stored in an image memory, the graphic accelerator including:

a storage control unit configured for receiving a plurality of pixels each having three types of color information including first type color information, second type color information and third type color information, deleting one of said three types of color information and storing color information of said plurality of pixels in said image memory such that said plurality of pixels include a first pixel having two types of color information excluding the first type color information and a second pixel having two type of color information excluding the second type color information; and

an interpolation process unit configured for restoring said plurality of pixels by interpolating the color information of said first pixel with the first type color information of said second pixel and interpolating the color information of said second pixel with the second type color information of said first pixel;

said graphic accelerator supplying said display data as an output according to the plurality of pixels stored in said image memory and interpolation result of said interpolation process unit.

2. The graphic accelerator according to claim 1, wherein said storage control unit stores the two types of color information of said first pixel in said image memory for each of the plurality of pixels arranged in a direction of even scan lines, and stores the two types of color information of said second pixel in said image memory for each of the plurality of pixels arranged in a direction of odd scan lines.

3. The graphic accelerator according to claim 1, wherein said storage control unit stores the two types of color information of said first pixel in said image memory for each of a first plurality of pixels arranged as a matrix and included in said plurality of pixels, and stores the two types of color information of said second pixel in said image memory for each of a remaining second plurality of pixels included in said plurality of pixels.

4. The graphic accelerator according to claim 1, wherein said storage control unit divides said plurality of pixels into a plurality of blocks, and deletes color information so that said plurality of blocks each include said first pixel and said second pixel, and

said interpolation process unit interpolates the color information of said first pixel with the first type color information of said second pixel of the same block as said first pixel and interpolates the color information of said second pixel with the second type color information of said first pixel of the same block as said second pixel.

5. The graphic accelerator according to claim 1, wherein said storage control unit deletes color information such that said plurality of pixels to be output include said first pixel, said second pixel, and a third pixel having two types of color information excluding the third type color information.

6. The graphic accelerator according to claim 5, wherein said plurality of pixels are arranged in said image memory such that a first line in which all pixels arranged in the scan direction of the screen are said first pixels, a second line which is next to said first line and in which all pixels arranged in the scan direction of the screen are said second pixels, and a third line which is next to said second line and in which all pixels arranged in the scan direction of the screen are said third pixels are repeatedly arranged.

7. The graphic accelerator according to claim 1, wherein each of said plurality of pixels written into said image memory includes the third type color information.

8. The graphic accelerator according to claim 7, wherein each of said plurality of pixels written into said image memory includes green color information.

9. A graphic accelerator generating display data based on data stored in an image memory, the graphic accelerator including:

a storage control unit configured for receiving a plurality of pixels each having color information and depth value information, and dividing said plurality of pixels into a plurality of blocks, said storage control unit further configured, on each block basis, for deriving a common depth value from the pixels of said block, storing the common depth value in said image memory, comparing a depth value of each pixel of the block with the common depth value stored in said image memory, and updating color information of the pixel to store the resulting information in said image memory according to a hidden surface removal process; and

a circuit configured for supplying said display data as an output employing the plurality of pixels stored in said image memory.

10. The graphic accelerator according to claim 9, wherein each of said plurality of pixels to be supplied as an input further includes transparency value information, and

said storage control unit derives a common transparency value for each block and stores the common transparency values in said image memory, performs an alpha blending process based on the common transparency values and stores the resulting information in said image memory.

11. The graphic accelerator according to claim 10, wherein said image memory includes,

a Z buffer for storing said common depth values derived from said respective blocks and,

a frame buffer for storing color information of each of said plurality of pixels and the common transparency information for each block.