Abstract

A system for formatting electronic binary image data, which may be in compressed raster form, into transposed or rotated raster form for storage or output, such as on a printing device, is disclosed wherein the image data is first assembled in a buffer in the form of vectors of run ends representing successive raster scan lines of an original image to be reproduced. The elements of an intermediate buffer are initialized to zero and the data is entered into the intermediate buffer by using each run end to set a bit in the intermediate buffer, with the bits being set in the buffer elements in correspondence with the respective raster positions of the run ends. The elements of the intermediate buffer containing the entered electronic data are then combined, such as by EXCLUSIVE-ORing, to create transposed or rotated raster data, which may stored or input to a suitable output device, such as a printer or display. The raster data may be compressed in the process and other processes, such as image reversal, may be carried out with facility.