To Press! Once an image is separated, the file must be saved in a format that is correct for the page make-up product that will follow. There are a variety of image file types, each of which can be effective in delivering good color images to the imagesetter at the time of output. Interestingly, there are no quality differences between file types; each image file is correct and effectively equal to its counterpart. Saving in TIFF, EPS or Scitex CT results in the same image in print, so the choice of file type is determined more by process and software than it is by any other criterion. Probably the most common file format is TIFF. This is an acronym for Tagged Image File Format, which was developed by Aldus Corp. (now Adobe) and Microsoft. The TIFF file allows for images in RGB, CMYK, and monochrome formats, and is extensible, meaning that the format can be extended by changes in software as they evolve. Apple Computer's Color Sync 2.0 software, for example, appends Color Sync profiles for scanners and displays into the TIFF file without modifying the bit-mapped components of the image. TIFF is also a platform-independent file format, allowing computers from A to Z to use the files created in TIFF without difficulty. PC computers write TIFF files with TIF suffixes, while Macintosh computers record TIFF as a file type; in either case, the structure of the file is the same. Image preview byte order is changed for each platform, but that doesn't prevent the two computer platforms from being able to read files written by the other. As a result, any image manipulation program that recognizes the TIFF file can open and modify TIFF images. Encapsulated PostScript EPS files are another flexible, platform-independent file type. EPS stands for Encapsulated PostScript. The Adobe PostScript language file conventions allow the recording of continuous-tone (bit-mapped) images inside a standard EPS file. The EPS standard also allows for vector math and typographic information to be written to an EPS file - either in conjunction with the continuous-tone material or independently - making EPS a very flexible file format. Like their TIFF cousins, EPS files are platform-independent, making them useful to a variety of computer systems. An EPS file made on a Macintosh computer can be moved to a UNIX or PC compatible computer with relative ease, and a PC EPS file can be moved to the Macintosh with little difficulty. Variations on an EPS theme EPS is, internally, an ASCII text-only file, and can be transmitted over modem wires, network cables, and fiberoptics with equal ease. Since it is text, and is easily manipulated, several variations exist for EPS with continuous-tone images. Single-file EPS documents contain the image and (optionally) a low resolution preview of the image. DCS piles DCS is an EPS-derivative file format developed by Quark, Inc. of Denver, Colorado. DCS stands for Desktop Color Separation, and was originally intended to bridge the gap between QuarkXPress software and a proprietary typesetting system. DCS allows for a low-resolution position document to be placed in a page layout program, and for the pre-separated high-resolution images to reside on a file server for later output to an imagesetter. DCS files consist of five separate documents, each one named after the master file, with ".c, .m, .y, and .k" appended to the filename. When a program such as QuarkXPress is printing to the imagesetter, it finds the related files on the server and downloads them to the imagesetter automatically. The theory is that the preview image can be smaller than full-resolution images, and can be cropped and sized in the page-layout program. These cropping and size modifications are passed to the individual color separations in the final output. UPS Documents with clipping paths EPS files are also the most reliable files to carry images with clipping paths. Adobe Photoshop software allows the creation of such paths with its pen tool. By outlining an image with the pen tools, the artist can mask backgrounds and internal areas from the final photograph. The outlines can then be saved with the photograph as an Encapsulated PostScript file with clipping paths. These same clipping paths can be exported to Adobe Illustrator for modification in that program, and then - if necessary - reimported into Photoshop software. Scitex CT format Scitex images, those scanned or created on Scitex's electronic prepress systems, are four color continuous-tone images useful for color separation on Scitex imagesetters or, when printed from QuarkXPress software, to any PostScript language imagesetter. Photoshop software can write any four-color or monochrome image in the Scitex CT format. The benefit of using the Scitex CT format is that the four colors are written in a compact form, preseparated by Photoshop software, and ready for output to an imagesetter. The format also makes the interchange between desktop systems and high-end prepress systems easier. Page make-up programs Images from Photo CD disc ultimately become printed photographs as part of complete pages. They are built into books and magazines, brochures, ads and pamphlets. A variety of page building applications exist to provide the page on which these images are printed. Page make-up programs include features that were formerly found on the drafting table - the ability to draw the basic page, delineate columns, put text, illustrations and photographs in place, and ultimately to generate a complete film record of the page and its contents. The sophistication of electronic page make-up goes far beyond the drafting table, though. In today's programs we have automatic page numbering, index creation, automatic continued to" and "continued from" column jumps, and control over many features that were entirely manual in the times of page paste-up. Two leading page make-up programs are Adobe PageMaker and QuarkXPress. These have dominated the scene since the development of desktop publishing systems in the mid-1980s. In their strive to excellence, the two competitive products have virtually identical features. Typographic, graphic, illustrative and printing features read like an encyclopedia in both cases. Other contenders in the race for page building on the computer are Frame Technologies' FrameMaker, Viva Press, and Corel's Ventura Publisher. Each has strengths that appeal to a part of the electronic graphic-arts market. Next Colorite Home Page OPTIMIZING PHOTO CD -- MENU