Line-based compression for digital image data

摘要

A method of compressing digital image data is provided that includes selecting an entropy code for encoding a line of pixels in the digital image data, wherein the entropy code is selected from a plurality of variable length entropy codes, using spatial prediction to compute a pixel predictor and a pixel residual for a pixel in the line of pixels, and selectively encoding the pixel residual using one of the entropy code or run mode encoding.

主权项

1. A method of compressing digital image data comprising:
selecting an entropy code for encoding a line of pixels in the digital image data, wherein the entropy code is selected from a plurality of variable length entropy codes; using spatial prediction to compute a pixel predictor and a pixel residual for a pixel in the line of pixels; and selectively encoding the pixel residual using one of the entropy code or run mode encoding, wherein selectively encoding comprises:
using run mode encoding to encode the pixel residual when a pixel residual of a previous pixel in the line of pixels is zero and selected neighboring pixels of the pixel have a same value; andusing the entropy code to encode the pixel residual when the pixel residual of the previous pixel in the line of pixels is not zero or the selected neighboring pixels do not have the same value.