Patent ID: 7397483
Filing Date: 2008-07-08
Classification: G06T

Abstract:
1. A color conversion method of converting three-dimensional input data representing an image by using a three-dimensional look-up table having rectangularly spaced grid points, grid positions of the three-dimensional look-up table having non-uniform intervals, the method comprising the step of performing interpolation processing using four grid points in eight grid points (P 000 =P(X 0 , Y 0 , Z 0 ), P 001 =P(X 0 , Y 0 , Z 1 ), P 010 =(X 0 , Y 1 , Z 0 ), P 011 =P(X 0 , Y 1 , Z 1 ), P 100 =P(X 1 , Y 0 , Z 0 ), P 101 =P(X 1 , Y 0 , Z 1 ), P 110 =P(X 1 , Y 1 , Z 0 ), P 111 =P(X 1 , Y 1 , Z 1 ) of a unit rectangular hexahedron which includes an input data value (X, Y, Z where X 0 ≦X≦X 1 , Y 0 ≦Y≦Y 1 , Z 0 ≦Z≦Z 1 ), wherein the interpolation processing comprises the steps of: obtaining weight values (u′, v′, w′), based on the input data value (X, Y, Z), wherein the weight values are expressed as follows: where a value of a predetermined constant (L) is greater than each of the grid intervals (X determining a relationship among the weight values (u′, v′, w′); calculating a value of the output data (P) for the input data value by tetrahedral interpolation using the output values for the four grid points and the weight values, based on determining result by the following equations: displaying a color converted image represented by the output data.