Sun Microsystems, Inc.

Jordan M Slott

Thomas Germano O'Neill

Tarik Ono

Richard G Fell

Benjamin Hebert

A method for compressing two color anti-aliased images takes advantage of the fact that when two color anti-aliased images are present, it is often the case that the two base colors appear in adjacent or continuous series or 'runs' of pixels representing the same color. According to one embodiment to the present invention, these runs are identified and then the color and run length are encoded to produce increased compression efficiency.

Method for compression of two-color anti aliased images

A system for compressing an image. The system determines a set of commonly occurring color values in the image and associates a designator with each commonly occurring color value. For each pixel in the image, the system identifies a color value for the pixel. If the pixel has a commonly occurring color value, the system substitutes the associated designator for the commonly occurring color value. Otherwise, if the pixel does not have a commonly occurring color value, the system adds the color value to a rare color list, and substitutes a special designator for the color value to indicate that the color value for the pixel is contained in the rare color list.

Method and apparatus for compressing images using color palettes and rare colors

Caching fonts on a display computer may be performed in order to reduce network bandwidth utilization and/or to improve CPU usage. Text commands may be recorded when they are executed to create a portion of a graphics image. These text commands may be used to update a data structure with information, and this data structure may be used to more efficiently transmit the text portions of the graphics image. A caching mechanism may be used wherein the font utilized by the text command is stored in the cache if a compatible font does not already exist in the cache. Once the font has been cached, subsequent text commands utilizing the font may be executed with a dramatic reduction in network bandwidth.

Caching fonts for improved bandwidth of transmitted text

A mechanism is provided that identifies certain classes of images that are likely to be re-used, and utilizes this information to manage a cache better. This may include flushing certain classes of images that are less likely to be re-used before flushing the classes that are more likely to be reused. In addition, or alternatively, other factors regarding the image may be utilized to determine whether or not caching of the image should occur.

Growing community of inventors

Durham, NC, United States of America

Jordan M Slott