Patent ID: 6897425

Claim:
An image signal processing method using a plurality of photosensitive cells, each of which is shifted from a geometric center of an adjoining photosensitive cell by half a pitch in at least one of a direction of row and a direction of column for separating incident light representative of a scene into three primary colors and executing photoelectric transduction with separated light, using said plurality of photosensitive cells as real pixels, converting image signals output from said plurality of photo sensitive cells to digital image data, and executing, by using said digital image data, interpolation for generating virtual pixels between said real pixels to thereby generate luminance data and chrominance data, said image signal processing method comprising: a first step of obtaining, when the image data are bidimensionally arranged such that green of the image data appears in a square lattice pattern, red pixel data from the real pixels facing each other in one diagonal direction at both sides of green, and obtaining blue pixel data from the real pixels facing each other in the other diagonal direction at both sides of green; a second step of generating, when either one of a red real pixel and a blue real pixel is a subject pixel to be dealt with, pixel data of a complementary color complementary to green by using a plurality of pixel data surrounding said subject pixel and positioned in a direction of correlation, while making a decision for improving correlation accuracy; a third step of generating pixel data to be interpolated in a virtual pixel from pixel data of a same color facing each other in at least one of a horizontal direction and a vertical direction by using the pixel data of the complementary color and the green pixel data; and a fourth step of limiting a frequency band in a direction perpendicular to a direction used for interpolation.