<p>In a method of forming an image in a form of pixels, the density distribution around the target pixel is obtained by processing image signals of pixels neighboring a target pixel. The target pixel is divided into plural sub-pixels in a form of matrix (n raws x m columns). The sub density distribution of the sub-pixels in the target pixel is assumed from the density distribution of the neighboring pixels. The density of each of sub-pixels is determined by multiplying the density of the target pixel, a constant P and a density ratio of the corresponding sub-pixels in the sub density distribution.</p>
