Abstract: One embodiment of the present invention sets forth a technique for performing undo operations on a graphics processing unit. The graphics processing unit is configured to copy a current buffer prior to performing modifications to the current buffer. The copy of the buffer is subtracted from the modified current buffer to generate a difference buffer. An undo operation is performed by subtracting the difference buffer from the modified current buffer. A sequence of difference buffers may be generated to provide multiple undo levels. Adding a subsequent difference buffers to the current buffer, generated by performing an undo operation, has the effect of performing a redo operation. The difference buffers are compressed for efficient storage and transmission between memory local to the graphics processing unit and system memory.

Abstract: One embodiment of the present invention sets forth a technique for performing undo operations on a graphics processing unit. The graphics processing unit is configured to copy a current buffer prior to performing modifications to the current buffer. The copy of the buffer is subtracted from the modified current buffer to generate a difference buffer. An undo operation is performed by subtracting the difference buffer from the modified current buffer. A sequence of difference buffers may be generated to provide multiple undo levels. Adding a subsequent difference buffers to the current buffer, generated by performing an undo operation, has the effect of performing a redo operation. The difference buffers are compressed for efficient storage and transmission between memory local to the graphics processing unit and system memory.

Abstract: A system or method of automated image processing that can automatically determine a color and transparency for a pixel with an observed color when given the pixel and a background reference color. A point in a color space can be automatically found by extrapolating in the color space based on two points in the color space that respectively correspond to or that respectively approximate the observed color and the given background reference color. A color for the given pixel that corresponds to or approximates the found point in the color space can also be calculated automatically. Based on the found point and the two points in the color space that respectively correspond to the observed color and the given reference color, a transparency for the pixel can be automatically found.

Abstract: The embodiments discussed herein involve flood filling a region with anti-aliasing. In forming a fill region, a candidate pixel can be included in the region based on a color of the pixel and also a color of a neighbor of the point. The inclusion basis may be a color distance between a seed color and the points, and a color distance between the seed color and the point's neighbor. Points in the region may be weighted according to their color distance relative to the seed color, where the color distance can also take into account alpha values. Flood filling may be anti-aliased by assigning alpha values to pixels in gaps between corners of the fill region, where an alpha value may be proportional to a point's contribution to the gap. Dimples in a fill region may be tested for and used to determine which of two flood fill algorithms to use.

Abstract: Flood filling a region with anti-aliasing. In forming a fill region, a candidate pixel can be included in the region based on a color of the pixel and also a color of a neighbor of the point. The inclusion basis may be a color distance between a seed color and the points, and a color distance between the seed color and the point's neighbor. Points in the region may be weighted according to their color distance relative to the seed color, where the color distance can also take into account alpha values. Flood filling may be anti-aliased by assigning alpha values to pixels in gaps between corners of the fill region, where an alpha value may be proportional to a point's contribution to the gap. Dimples in a fill region may be tested for and used to determine which of two flood fill algorithms to use.

Abstract: A system or method of automated image processing that can automatically determine a color and transparency for a pixel with an observed color when given the pixel and a background reference color. A point in a color space can be automatically found by extrapolating in the color space based on two points in the color space that respectively correspond to or that respectively approximate the observed color and the given background reference color. A color for the given pixel that corresponds to or approximates the found point in the color space can also be calculated automatically. Based on the found point and the two points in the color space that respectively correspond to the observed color and the given reference color, a transparency for the pixel can be automatically found.