Method and apparatus for providing resource-optimized delivery of web images to resource-constrained devices

摘要

A method and apparatus in which regions of a web image containing textual information (text-containing regions) and regions of the image not containing textual information (non-text-containing regions) are identified and differentially transcoded so as to provide an image quality for the text-containing regions which is superior to (i.e., less degraded relative to) the image quality of the non-text-containing regions. A data structure is generated based on the web image, the data structure containing at least one coded representation for each of the text-containing regions and a plurality of coded representations of each of the non-text-coniaining regions. A coding of the web image is generated from the data structure by selecting coded representations based on characteristics of a particular target client device and the bandwidth of a communications channel. Various coded representations may be generated by down-sampling the given region, or reducing the color depth or number of gray levels thereof.