Patent ID: 6205248
Filing Date: 2001-03-20
Classification: H04N

Abstract:
A method of compressing non-transposed data comprising the steps:(a) receiving successive non-transposed columns of binary pixels representing data on a document using a document scanner, with said successive non-transposed columns of binary pixels including a first non-transposed column of binary pixels and a last non-transposed column of binary pixels to be processed, said successive non-transposed columns of binary pixels being derived from the same document;(b) using an examining window to extend over a predetermined number of said successive non-transposed columns along a direction which is perpendicular to the direction of said columns so as to present a row of said binary pixels, with said using step using only one binary pixel from each of said non-transposed columns of binary pixels for said row of binary pixels;(c) generating a change of color bit for each of the binary pixels in the examining window, starting with said first non-transposed column of binary pixels while said examining window is moved towards said last non-transposed column of binary pixels;(d) examining a pixel in a target row under consideration in said window with regard to a reference row and designating coding according to a predetermined code which uses said reference row for compressing pixels in said target row, with said reference row and said target row being perpendicular to said successive non-transposed columns of binary pixels;(e) compressing said target row starting with said first non-transposed column of binary pixels while said examining window is moved towards said last non-transposed column of binary pixels, with said compressing step (e) being initiated after receiving said first non-transposed column of binary pixels but before said last non-transposed column of binary pixels is received;(f) repeating steps (b), (c), (d), and (e) for the remaining non-transposed columns of binary pixels on the document.