In an image processing device, a sampling portion selects, as a target line, each of four reference lines that pass through a pixel of interest in a 3×3 target pixel group. When a difference between data among a pair of neighboring pixels, positioned along the target line, is within a predetermined first selection reference range, and with respect to at least one of two areas on both sides of the target line, all differences among data of three neighboring pixels that exist in the area are within a predetermined second selection reference range, the sampling portion selects the pair of neighboring pixels as the sample pixels. When a difference between data of the pixel of interest and an average value of the sample pixels exceeds a predetermined correction reference range, the device corrects the data of the pixel of interest to a value based on the sample average value.