Patent ID: 6185325
Filing Date: 2001-02-06
Classification: G06T

Abstract:
An image transforming method, in which a first picture element value of each of picture elements constituting a color image is replaced by a second picture element value that is set to have correspondence to the first picture element value by a predetermined transformation formula, the method comprising:dividing a multi-dimensional color space into a plurality of blocks in units of a block having a predetermined size,carrying out an operation with the transformation formula with respect to coordinates of each of vertexes of each block, transformed values of the coordinates of vertexes of each block being thereby calculated previously, andcarrying out an interpolating operation with respect to the first picture element value and in accordance with weight factors of the vertexes, which weight factors are determined in accordance with a position of the first picture element value in a block, and the transformed values of the coordinates of the vertexes of the block, which contains the first picture element value, the second picture element value being thereby calculated,wherein the improvement comprises the steps of:i) in cases where a block having a size different from the predetermined size is contained in the plurality of the blocks, replacing said block having the different size by a virtual block, which has a size identical with the predetermined size, transformed values of coordinates of vertexes of said virtual block being then calculated from the transformed values of the coordinates of the vertexes of said block having the different size,ii) previously storing information, which represents a transformed value table, and information, which represents a factor table, in a memory, said transformed value table recording the transformed values of the coordinates of the vertexes with respect to each of the blocks, including said virtual block, said factor table recording vertexes, which have weight factors other than 0, and the weight factors of the vertexes, which have weight factors other than 0, with respect to each of positions in a block, andiii) carrying out the interpolating operation by utilizing only the vertexes, which have weight factors other than 0, and in accordance with the transformed values, which have been recorded in said transformed value table, and the vertexes and their weight factors, which have been recorded in said factor table.