An image processing apparatus processes an image obtained by capturing inside of a lumen of a living body. The image processing apparatus includes: a contour edge region extracting unit configured to extract a contour edge region of an examination target from the image; an examination region setting unit configured to set an examination region in the image so as not to include the contour edge region; and an abnormal structure identifying unit configured to identify whether a microstructure of a surface of the examination target is abnormal, based on texture information of the examination region.