1. An image processing apparatus for conducting edge enhancement processing on an original image, comprising: an enhancement amount calculation unit for calculating a density enhancement amount for each edge pixel of the original image, the edge pixel being a pixel in an edge area in the image; an enhancement amount processing unit for correcting the density enhancement amount for each edge pixel in a manner to reduce variations in the density enhancement amounts in the overall edge area; a density processing unit for correcting a density of each edge pixel of the original image in a manner to reduce variations in densities in the overall edge area; and a density calculation unit for calculating an enhanced density of each edge pixel from the corrected density and the corrected density enhancement amount.