Patent ID: 8290308

Claim:
A non-transitory computer readable storage medium storing an interpolation method determination program for making a computer execute a process for determining an interpolation method for interpolating respective pixel values of plural pixels which do not exist in an input image and which are positioned on a straight line, the process comprising: a target pixel selection by selecting, sequentially in accordance with a designated selection sequence direction, one pixel from among the plural pixels as a target pixel for which the interpolation method needs to be determined; calculating a local correlation value for each one of designated plural correlation calculation directions using a pixel value of each of a first number of at least one first pixel existing in the one of the plural correlation calculation directions viewed from the target pixel and a pixel value of each of a second number of at least one second pixel existing in a direction opposite to the one of the plural correlation calculation directions viewed from the target pixel; a cumulative correlation value calculation obtaining a plurality of cumulative correlation values, the plurality of cumulative correlation values being a set of correlation values to be calculated for each of the plural pixels sequentially one after another in accordance with the selection sequence direction starting from a head pixel based on a value given to the head pixel, the head pixel being a pixel at the head of a sequence in accordance with the selection sequence direction among the plural pixels, and the cumulative correlation value calculation comprising calculating the cumulative correlation value for the one of the plural correlation calculation directions in relation to the target pixel using at least the local correlation value corresponding to the one of the plural correlation calculation directions and the cumulative correlation value having been calculated, in correspondence with one of the plural correlation calculation directions, for a prior pixel selected immediately prior to selecting the target pixel; a direction selection by selecting one of the plural correlation calculation directions according to the cumulative correlation values corresponding to the respective plural correlation calculation directions; and an interpolation-use pixel determination by determining plural pixels used for interpolating the target pixel according to at least either the local correlation value which corresponds to the correlation calculation direction selected, or the cumulative correlation value which corresponds to the correlation calculation direction selected.