Patent ID: 6160918
Filing Date: 2000-12-12
Classification: G06F,H03M,H04N

Abstract:
A method for compressing an image, comprising the steps of:a. dividing the image into at least one image set, wherein each image set is a two-dimensional array of pixels having a number of columns M and a number of rows N; andb. for each image set:i. transforming the image set into a set of coefficients using a reversible transform, wherein the reversible transform comprises a two-stage Hartley transform, said two-stage Hartley transform comprising, in any order, one pass of a one-dimensional row Hartley transform and one pass of a one-dimensional column Hartley transform, each pass of the one-dimensional row and the one-dimensional column Hartley transform being computed using a matrix representation requiring at most two distinct multiplication operations when multiplying a vector;ii. quantizing each coefficient of the set of coefficients; andiii. coding each quantized coefficient of the set of coefficients in accordance with an entropy code.