Patent ID: 6304671
Filing Date: 2001-10-16
Classification: G06T,H04N

Abstract:
An image processing apparatus that carries out color correction of a multi-color image and outputs the color-corrected image, the multi-color image being expressed by coordinates that correspond to predetermined numbers of tones in three dimensions in a color space, said image processing apparatus comprising:an input unit configured to input color image data specified by a specific combination of coordinates with respect to each pixel included in the multi-color image;a first memory configured to store lattice point information in the form of a lattice point information table, said lattice point information including coordinates of lattice points that are obtained by dividing said color space by a predetermined number in each dimension, which is smaller than a number of tones in each dimension;a second memory configured to store color correction data, which relate to a quantity of color correction, corresponding to each lattice point in the from of a color correction table;a lattice division identification unit configured to identify a specific lattice division in which the color image data is included, among a plurality of lattice divisions defined by adjoining lattice points in the three dimensions of said color space, based on the lattice point information;an image data conversion unit configured to convert the color image data into coordinates of a reference lattice point, which represents a base point among lattice points constituting the specific lattice division, and offset coordinates, which represent a deviation of the color image data from the coordinates of the reference lattice point in the three dimensions;a third memory configured to store interpolation data including lattice point specification data and weighting coefficient data, which are required for interpolating said color correction table and specifying color correction data corresponding to the color image data, corresponding to the offset coordinates in the form of an offset correction table, the lattice point specification data specifying at least part of four lattice points used for interpolation, the weighting coefficient data determining values multiplied by color correction data corresponding to the four lattice point; anda color correction unit configured to read interpolation data corresponding to the offset coordinates from said offset correction table, read color correction data corresponding to the reference lattice point and predetermined lattice points adjoining to the reference lattice point from said color correction table, carry out interpolation of the color correction data with the interpolation data, and output a result of the interpolation as corrected color image data,wherein the image processing apparatus uses the offset correction table so the interpolation is performed without conditional jumps so as to attain high-speed image processing.