Patent ID: 7855739

Claim:
An image signal processing apparatus inputted with original image data in which plural color components periodically appear in each column of sampling points arranged in a matrix at a repetition period of n lines, and for generating target image data different from the original image data in a vertical sampling period, comprising: a data holding part for holding plural lines of the inputted original image data, which are in a line range of a specified width and have a specified positional relation to each other, the original image data being image data that exists before color separation is performed; a target image data generation part for generating the target image data at a target line of a position corresponding to the line range of the original image by weighting the original image data of the plural lines held in the data holding part for each line and adding the weighted image data of the plural lines; and a factor setting part for setting, according to the target line, weighting factors for the respective lines used in the weighting and addition performed in the target image data generation part, wherein the factor setting part determines the weighting factors on the basis of a trap characteristic of attenuating, in the target image data, a frequency component corresponding to 1/n of a vertical sampling frequency of the original image and the repetition period of the color components to perform format conversion before the color separation, and a mutual positional relation between a vertical sampling point corresponding to each line of the original image data held in the data holding part and a vertical sampling point corresponding to the target line.