Patent ID: 7280709

Claim:
A scan line interpolation device for generating an interpolated pixel on an interpolated scan line from pixels disposed on at least four consecutive scan lines, including at least two scan lines on each side of the interpolated scan line, the scan line interpolation device comprising: a pattern matching means for calculating pattern similarity values for a plurality of pixel block pairs, each pixel block pair including two pixel blocks disposed in point-symmetrical positions on opposite sides of the interpolated pixel, each of the two pixel blocks including an identical number of said pixels, the pattern similarity value of each pixel block pair being calculated from values of the pixels in its two constituent pixel blocks; a similar edge decision means for deciding whether similar edges are present in corresponding positions in the two pixel blocks constituting each said pixel block pair, on the basis of differences between the pixel values of pixels disposed on mutually adjacent scan lines in one of the pixel blocks, aligned in a direction perpendicular to the scan lines, and differences between the values of pixels disposed in corresponding positions in the other pixel block in the same pixel block pair; an interpolation direction decision means for selecting an interpolation direction corresponding to the positions of the two pixel blocks in a pixel block pair having a greatest similarity, as calculated by the pattern matching means, among the pixel block pairs in which the similar edge decision means decides that similar edges are present; and an interpolation means for generating the interpolated pixel by using, as reference pixels, the pixels disposed closest to the centers of the two pixel blocks in the pixel block pair corresponding to the interpolation direction selected by the interpolation direction decision means.