Drawing processing apparatus and method for compressing drawing data

A drawing processing apparatus comprising:

• a rasterizer which rasterizes a drawing primitive on a per rectangular pixel set basis, the rectangular pixel set containing at least one pixel, to produce pixel data of the drawing primitive;
• and
• a shader which receives the pixel data of the drawing primitive from the rasterizer on the per rectangular pixel set basis to perform drawing computation on the drawing primitive, wherein:
• the rasterizer includes a compression encoding unit which compressively encodes information relating to the sub-pixels on the per rectangular pixel set basis by run length encoding in accordance with the number of the same contiguous pieces of data;
• and
• the shader includes a decompressing unit which decompresses the information relating to the compressively encoded sub-pixels for the pixel data of the drawing primitive received on the per rectangular pixel set basis from the rasterizer, wherein
• the information relating to the sub-pixels is data, expressed in binary form, resulting from a determination made on a per sub-pixel basis as to whether a sub-pixel is inside or outside the drawing primitive, and the binary value of sub-pixels along with the non-binary value of pixels are run-length encoded.

A method performed by a computer for compressing drawing data, comprising:

• rasterizing by the computer a drawing primitive on a per rectangular pixel set basis, the rectangular pixel set containing at least one pixel;
• and
• compressively encoding by the computer information relating to sub-pixels on the per rectangular pixel set basis by run length encoding in accordance with the number of the same contiguous pieces of data, wherein
• the information relating to the sub-pixels is data, expressed in binary form, resulting from a determination made on a per sub-pixel basis as to whether a sub-pixel is inside or outside the drawing primitive, and the binary value of sub-pixels along with the non-binary value of pixels are run-length encoded.

A method performed by a computer for compressing drawing data, comprising:

• scanning by the computer a drawing area on a per rectangular pixel set basis, the rectangular pixel set containing at least one pixel, to determine on a per sub-pixel basis whether a sub-pixel is inside or outside a drawing primitive;
• and
• compressively encoding by the computer information relating to the sub-pixel on the per rectangular pixel set basis by run length encoding in accordance with the number of the same contiguous pieces of data, wherein
• the information relating to the sub-pixels is data, expressed in binary form, resulting from a determination made on a per sub-pixel basis as to whether a sub-pixel is inside or outside the drawing primitive, and the binary value of sub-pixels along with the non-binary value of pixels are run-length encoded.

A computer-readable recording medium having a computer program stored thereon, said computer program causing a computer to define a data structure of drawing data of a drawing primitive, wherein:

• the drawing data contains pixel data of the drawing primitive rasterized by the computer on a per rectangular pixel set basis, the rectangular pixel set containing at least one pixel;
• and
• information relating to sub-pixels is compressively encoded by the computer on the per rectangular pixel set basis by run length encoding in accordance with the number of the same contiguous pieces of data, wherein
• the information relating to the sub-pixels is data, expressed in binary form, resulting from a determination made on a per sub-pixel basis as to whether a sub-pixel is inside or outside the drawing primitive, and the binary value of sub-pixels along with the non-binary value of pixels are run-length encoded.

A computer-readable recording medium having a computer program stored thereon, said program causing a computer to execute the steps of:

• receiving by the computer, on a per rectangular pixel set basis, pixel data of a drawing primitive rasterized on the per rectangular pixel set basis, the rectangular pixel set containing at least one pixel;
• and
• compressively encoding by the computer information relating to sub-pixels on the per rectangular pixel set basis by run length encoding in accordance with the number of the same contiguous pieces of data, wherein
• the information relating to the sub-pixels is data, expressed in binary form, resulting from a determination made on a per sub-pixel basis as to whether a sub-pixel is inside or outside the drawing primitive, and the binary value of sub-pixels along with the non-binary value of pixels are run-length encoded.

A computer-readable recording medium having a computer program stored thereon, said program causing a computer to execute the steps of:

• receiving by the computer drawing data with information relating to sub-pixels compressively encoded by run length encoding on a per rectangular pixel set basis, including pixel data of a drawing primitive rasterized on the per rectangular pixel set basis, the rectangular pixel set containing at least one pixel;
• and
• acquiring by the computer a run length code indicative of a starting position at which a significant value appears for the first time in each row or each column of a data matrix of the sub-pixels within the rectangular pixel set and the number of contiguous significant values from the starting position in the row or column to decode the data matrix of the sub-pixels within the rectangular pixel set on a per row or per column basis, wherein
• the information relating to the sub-pixels is data, expressed in binary form, resulting from a determination made on a per sub-pixel basis as to whether a sub-pixel is inside or outside the drawing primitive, and the binary value of sub-pixels along with the non-binary value of pixels are run-length encoded.