Image processing apparatus, image processing method, image processing program, and storage medium

An image processing apparatus to perform an edge intensifying processing of an image, the image processing apparatus comprising:

• an obtaining unit configured to obtain image data generated by reading a document optically, the image data being composed of pixels aligned in a main scanning direction and a sub-scanning direction perpendicular to the main scanning direction;
• a calculating unit configured to obtain an edge direction of an image and a variation amount indicating a magnitude of change in a luminance value in the edge direction of a predetermined pixel of the image based on a luminance value of the predetermined pixel and a luminance value of pixels neighboring the predetermined pixel;
• a setting unit configured to set an intensity of the edge intensifying processing based on an intensity of a processing determined based on a difference between resolution in the main scanning direction and resolution in the sub-scanning direction in accordance with the obtained edge direction and the obtained variation amount of the luminance value in the edge direction;
• and
• a processing unit configured to perform the edge intensifying processing of the image in accordance with the intensity set by the setting unit;
• wherein, in a case where the resolution of the image data in the sub-scanning direction is higher than the resolution in the main scanning direction, the setting unit sets the intensity of the edge intensifying processing corresponding to a predetermined variation amount that is higher when the edge direction is the sub-scanning direction than when the edge direction is the main scanning direction.