Patent ID: 8837838

Claim:
An image processing apparatus comprising: a first edge extraction unit which determines an edge pixel of image data constituting an edge of an object by using pixel values of pixels of the image data so as to extract the edge pixel as a first edge; an edge processing unit which performs edge processing on the image data so as to change a pixel value of an edge pixel constituting the edge of the object in the edge processing or a pixel value of an adjacent pixel to the edge pixel in an opposite edge direction; a second edge extraction unit which extracts the edge pixel or the adjacent pixel having the pixel value changed by the edge processing as a second edge; a third edge extraction unit which extracts the first edge and the second edge as a third edge; and a gradation processing unit which performs gradation processing on the image data on which the edge processing has been performed, wherein the gradation processing unit switches contents of the gradation processing on the basis of whether a pixel of the image data on which the edge processing has been performed is a third edge pixel constituting the third edge or a no-third edge pixel not constituting the third edge so as to enhance a third edge region of the third edge by the gradation processing as compared with a region other than the third edge region.