A region-of-interest method for texturally-rich document image coding

Region-of-interest (ROI) techniques are often utilized to improve coding for detailed regions in natural still-image coding standards such as JPEG2000 [1], but no specific method is stated for determining the ROI map. In this paper, an ROI-based method, in which rectangular regions are extracted using document image analysis (DIA), is proposed specifically for document image coding. These rectangular regions can be efficiently coded using wavelets, and DIA may also be used to distinguish between important and unwanted foreground regions, allowing further coding gains (as illustrated in one of the example documents in the paper). Compared to multilayer methods currently used for document image coding [2], the method is simpler and scalable, while improving visual quality and the peak-signal-to-noise ratio (PSNR).