In an image processing apparatus, a matrix for an arbitrary pixel (to be an observed pixel) on the original image is set up so that the density of the observed pixel and that of a target pixel which is located in the direction along which shadows are formed are compared to determine a maximum value of density of the two. If the density of the observed pixel is greater than that of the target pixel or pixels, the density of the target pixel is converted into a predetermined level of density, whereas if the density of the observed pixel is less than that of the target pixel, no conversion of density is made. This procedure is repeatedly performed for the entire image information to thereby create shadows having a designated length and complete a shadowing image. Then, the shadowing image is combined with the original image, whereby a shadowed image is complete.