Abstract: An apparatus and method for displaying a digitized document such as a facsimile transmission signal on a low-resolution output device such as the screen of a personal computer. The compressed digital source signal is linearly reduced into an array of pixels by passing the source signal through a filter that groups source pels into clusters. The combined weight of the black or white source pels within each cluster is translated into a grey-scale value for the corresponding target pixel. The determination of the size of the filter domain, and the minimization of source pel duplication within the line are achieved through simple and rapid calculations. Any duplications or source pels resulting from incompatibility between the lengths of a line and the width of a filter domain are evenly distributed by stretching, when necessary, the source runs. The process is further expedited by direct transformation of stretched source runs into target pixels.