摘要:
A method, system and computer program product for progressively encoding a digitized color image with M distinct colors by assigning each of the M distinct colors to an associated subset of pixels in the image, is provided. This involves: (a) initializing a tree structure with at least one starting leaf node comprising a subset of the M distinct colors; (b) determining at least one representative color for each starting leaf node; and (c) growing the tree structure by (i) selecting a leaf node n to become a non-leaf node based on the combined distortion and entropy rate resulting from turning the leaf node into the non-leaf node; (ii) allocating each color in leaf node n to one of the two new leaf nodes; (iii) determining a representative color for each new leaf node; and (iv) encoding the resulting index information, representative color information, and pixel information.
摘要:
The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder.
摘要:
The invention is directed at a method and apparatus for determining compression state information which is to be used in the compression of data being transmitted between two communicating parties. The method of determining the compression state information for use in interactively compressing data comprises the steps parsing the data to determine a hierarchical data structure of the data; traversing a shared hierarchical node index to determine common compression state information entries between the hierarchical data structure and the hierarchical node index; and selecting at least one of the common compression state information entries for use in compressing the data.
摘要:
The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder.
摘要:
Methods are described for configuring a quantizer to achieve improved end-to-end distortion performance when transmitting encoded source data over a noisy channel. The codebook and partitioning are selected using an iterative process of determining an updated codebook and an updated partition space, where the updated codebook is based, in part, on the average symbol error probability of the channel. Complete knowledge of the transitional probabilities of the channel is not required. Variants of the iterative process are described.