Patent ID: 7486837

Claim:
An image conversion method for performing image upsizing or image downsizing on a first image to convert the first image into a second image, comprising: a first step of acquiring, for each pixel of the first image, values of a plurality of parameters of a predetermined illumination equation, wherein the predetermined illumination equation defines a brightness as a function of the plurality of parameters and a display value of the pixel, wherein the plurality of parameters are determined by optical characteristics associated with a photograph subject and different from the display value of the pixel; a second step of specifying, for each of the parameters, a homogeneous region including pixels which are similar in value of the parameter; a third step of increasing or decreasing density of each of the parameters, in each of the homogeneous region specified at the second step, according to details of the image upsizing or image downsizing; and a fourth step of determining the brightness of each pixel of the second image using the values of the parameters obtained after the density increasing or decreasing of the third step.