Pre-Press Picture Processing in the Graphic Arts Industry

The graphic arts industry embraces all aspects of picture and graphic preparation prior to the actual running of a printing press. Electronic equipment is now available for much of this work, including such processes as the scanning and color separation of color material, the storage and transmission of data within a plant or to remote sites, the spatial manipulation of images in the assembly of pages, and the preparation of a final printing surface. The requirements of the printing industry differ from those of most other applications of image processing, both because of the wholly subjective judgment of the product by the user, and because any technological methods introduced into the printing industry must withstand comparison both in economy and quality, with wellestablished craft methods. This has led to the evolution of specialized equipment. Much of this is highly sophisticated, including very precise input and output scanning systems, the latter now often employing lasers. The signal processing involves large quantities of data at high speeds and special techniques have been devised. The principles involved and some of the current machines in which they are used are described in the paper, which ends with some speculations on future development.