An image processing apparatus includes a color intersection point determination and contour point extraction unit configured to raster-scan a multivalued image by using a pixel matrix having a predetermined size, to determine whether a target point is a color intersection point for dividing a contour for forming a boundary between pixels having a different value from each other, according to states of a plurality of pixels in the pixel matrix, and to extract a contour point for forming the boundary between the pixels having a different value from each other; and a contour information reconstruction unit configured to, by using color intersection points determined by the color intersection point determination and contour point extraction unit and contour points extracted thereby, generate contour information including contour lines each being sectioned by the color intersection points.