Patent ID: 7657112

Claim:
An image processing method, comprising: a processor performing the steps of: executing a filter process on an image data set, to extract a line noise component that extends in a sub scanning direction and/or a main scanning direction within an image represented by the image data set; and subtracting image data that represents the line noise component from the image data set, to remove the line noise component from the image; wherein: a preprocess, which reduces drastic changes in pixel values of the image data set in a first direction perpendicular to the sub scanning direction or a second direction perpendicular to the main scanning direction, is executed on the image data set prior to the filter process, wherein in the case that the preprocess is that which reduces drastic changes in pixel values of the image data set in the first direction, the preprocess comprises the steps of: obtaining difference data that represents the difference between pixel data, which are adjacent in the first direction; executing a process that decreases the absolute value of the difference data having values that exceed a predetermined threshold value; and cumulatively adding the processed difference data in the first direction, wherein in the case that the preprocess is that which reduces drastic changes in pixel values of the image data set in the second direction, the preprocess comprises the steps of: obtaining difference data that represents the difference between pixel data, which are adjacent in the second direction; executing a processes that decreases the absolute value of the difference data having values that exceed a predetermined threshold value; and cumulatively adding the processed difference data in the second direction.