Abstract A computer program system, CRISP, for crystallographic image processing (CIP), has been developed. CRISP runs on a standard personal computer (PC), and is considerably faster than previous systems for CIP. High-resolution electron microscopy (HREM) images are digitized by a CCD camera and directly transferred to the PC via a frame grabber. CRISP has been designed with strong emphasis on user friendliness. Thus, installation takes only a few minutes, a full processing of an HREM image takes less than 20 minutes, all operations are carried out with a mouse, and all the crystallography needed for 2D analysis of images is programmed into CRISP.