Patent ID: 6137907
Filing Date: 2000-10-24
Classification: H04N

Abstract:
A method of post-processing an electronic image of a document that was first divided into a plurality of tiled rectangular blocks of pixels and then processed so that each of the plurality of tiled blocks were classified as a one of a set of classifications including a text document type block, a contone document type block and halftone document type block, the method comprising the steps of:determining whether a first block of pixels among said plurality of blocks of pixels was classified as a halftone block; and,when said first block of pixels is determined to be classified as a halftone block, for a first pixel within the first tiled block:calculating a first busyness measure value of said first pixel within said first block;determining whether the first busyness measure value of the first pixel within said first block is less than a first predetermined threshold value MinPixelS.sub.ij Threshold;when the first busyness measure value of the first pixel within said first block is less than said predetermined threshold value MinPixelS.sub.ij Threshold, determining whether a video intensity level Video.sub.-- Level(1) of the first pixel within said first block is greater than a second predetermined threshold value White.sub.-- Threshold;when the video intensity level Video.sub.-- Level(1) of the first pixel within said first block is greater than said second predetermined threshold value White.sub.-- Threshold, re-classifying the first pixel within said first block as a text document type pixel; and,when the video intensity level Video.sub.-- Level(1) of the first pixel within said first block is less than said second predetermined threshold value White.sub.-- Threshold, re-classifying the first pixel within said first block as a contone document type pixel.