Abstract: A method and system for efficiently rotating an image in a first raster, by any angle, onto a second raster of much higher resolution, and also for generating a page image in a high-resolution raster from a plurality of contone images, input in lower resolutions, with arbitrary orientation angles. The system uses serially organized buffer memories to store input pixels relevant to a group of output raster lines at a time and calls for repeatedly reading out the values in sequence, once for each line of the group, and selecting the relevant values on the fly. More specifically, pixels are stored in two buffer memories, corresponding to two lines straddling the back-mapped group, and values are selected between their respective readout streams according to which elementary pixel areas each back-mapped raster line traverses. Concurrently the segment lengths of such traversal are computed and paired with the selected pixel values.