Progressive color block coding of bilevel scanned documents

Some preliminary results are presented on a simple progressive code for scanned 300 dpi documents. The effectiveness of the standard CCITT codes as a function of document resolution is determined. Extensions to the technique of document resolution are examined. For higher-resolution scanning, e.g. 300 dpi, a pyramid of the information source which allows for a tradeoff between the compression achieved and the quality of the representation is proposed. A progressive code that first generates a color block image that may be useful for identification of the document is proposed. Progression in quality corresponds to 100 dpi binary images, 100 dpi gray scale images, 300 dpi binary images, and finally 300 dpi gray-scale images. Each stage in the progressive code is based on the data available at the previous stage. The performance of the progressive code is examined