PROBLEM TO BE SOLVED: To provide an image processor for enhancing the visibility of the linear pattern in a target image.SOLUTION: The image processor includes a linear pattern detection part for detecting a line value showing the linear pattern of a dark or bright line having a continuity in a specific direction at every pixel in the target image, a first weight parameter determination part in relation to an image processing filter constituted of a first weight function wherein a first weight becomes small as the difference between the pixel value of the filter center pixel present within a filter range and the pixel value of the filter peripheral pixel becomes large and a filter processing part for applying the image processing filter constituted of the first weight function including first and second parameters determined at every pixel of the target image to the respective pixels of the target image to calculate the pixel values of the respective pixels of an output image.
