Patent Document ID: 5568571
Application ID: 07989820
Patent Status: 1

Claim One:
1. A digital image processing apparatus comprising in combination; A. means for receiving a scaler image file of scaled pixel values; B. means for segmentation of the scaled pixel values into graphics blocks and non-graphics blocks, the segmentation means including: 1. means for determining at least a first edge threshold from the scaled pixel values wherein the edge threshold is determined according to the following formula: EQU TV=a.times.((LNG-DNG)/b+DNG); where: a and b are numerical coefficients; TV=edge threshold; LNG=lightest non-white scalar pixel value; and DNG=darkest non-black scalar pixel value; and 2. means for applying at least one edge detection filter to each scalar pixel value and tagging as an edge the scalar pixel values satisfying the conditions of the edge detection filter; C. means for developing a binary image file derived from the scalar image file, the developing means including: 1. means for applying a text threshold to the non-graphics blocks in the scalar image file to convert each scaled pixel non-graphic value into a first binary value representing text or alternatively a second binary value representing background for the text; and 2. means for applying a graphics threshold to graphics blocks in the scalar image file to convert each scaled pixel graphic value into a first binary value representing one color or alternatively a second binary value representing another color; and D. means for compressing the binary image file to yield a compressed image file for subsequent decompression and digital processing of the compressed image file.