Abstract: Embodiments of the present invention comprise a method for transmitting map data, a method for displaying map data, a system for processing and displaying map data, and a method for rendering line segments on a pixel display. A preferred method for transmitting map data comprises receiving, layering, and simplifying map data and transmitting some of the simplified data. A preferred method for displaying map data comprises receiving compressed map data, decompressing the received data, and rendering the decompressed data on a display device. A preferred system for processing and displaying map data comprises a map database, a map generation sub-system, a map rendering sub-system, and a display device. A preferred method for rendering line segments on a pixel display, comprises, for a line segment from a first endpoint to a second endpoint, rounding off the slope of the line segment and calculating pixel locations based on that rounded off slope.

Abstract: In one aspect of a preferred embodiment, the present invention comprises a system for video compression comprising a video preprocessor; a predictor configured to receive video data from the preprocessor; and an encoder configured to communicate with the predictor. Preferably, the preprocessor comprises a colorspace converter, a frame activity detector, and a subsampler, the predictor comprises a frame differencer and a reference frame handler, and the encoder comprises an error image encoder and an image adder. In another aspect, the invention comprises a system for video decompression comprising a predictor and a decoder configured to communicate with the predictor. Preferably, the predictor comprises a reference frame handler and wherein said decoder comprises an error image decoder and a colorspace converter.