Fast segmentation of the JPEG compressed documents

We present a novel technique for segmentation of a JPEG-compressed document based on block activity. The activity is measured as the number of bits spent to encode each block. Each number is mapped to a pixel brightness value in an auxiliary image which is then used for segmentation. We introduce the use of such an image and show an example of a simple segmentation algorithm, which was successfully applied to test documents. The document is segmented into characteristics regions labeled as background, halftones, text, graphics, and continuous tone images. The key feature of the proposed framework is that the desired region can be identified and cropped (or removed) from the compressed data without decompressing the image. (C) 1998 SPIE and IS&T. [S1017-9909(98)01002-2].