<title>Error image in error diffusion</title>

The concept of an error image is defined for the error diffusion algorithm. Ordinarily hidden from view, the error image is a visual representation of the internally generated errors from which the algorithm derives its name. In this paper, it is shown that the error image contains a linear component of the input image, which induces edge enhancement in the output error diffusion image. Examples are shown for three different error weight distributions: a 1-D one- ahead distribution, the standard 4-element distribution, and a 12-element error distribution. The amount of edge enhancement in the corresponding algorithm is shown to vary with the amount of input image information present in the error image.