Working in RGB Red, green and blue are the additive primary colors, and the colors that make visible light - and video displays work. The vibrancy and intensity of color on a computer monitor are impressive. The conversion from RGB to four colors for printing can be a challenge, as the method chosen for conversion has a tremendous effect on the appearance of the final image. RGB has several benefits. The three-color space is used by photo retouchers to get maximum color saturation from an image before committing it to photo printing or a film recorder. Multimedia specialists work with RGB While the low cost of Photo CD scans is attractive it represents only one reason to use Photo CD A more compelling reason is improved workflows With a digital image scanned on a Photo CD system it is possible to reduce the steps in prepress production Graphic arts projects can be completed in less times and with more control over image quality than with other sources of digital and conventional color images There are a variety of techniques for getting a Photo CD image from the disc and turning it into a reproducible image for prints All of these techniques are relatively simple and most result in an image that is pleasing and effective in print The quality of the reproduction can be enhanced by the correct use of computer programs and Photo CD image conversion software One can open a Photo CD image in a number of color spaces making the options even more varied The process begins with Photo CD to RGB (red, green ,blue) with a subsequent conversion to the four printing colors - cyan, magenta ,yellow, black (CMYK) This method is probably the most common method for working with Photo CD discs though perhaps not the bests Adobe Photoshop software allows access to Photo CD images in RGB by using the Open command The software that accomplishes this task is a Kodak product called CMS Photo CD that is located in the Plug-in folder of the Photoshop program This same software allows images to be opened in the more obscure CIELAB color space Extra-cost options for Adobe Photoshop software include a list of plug-in products from Kodak as well as other suppliers that open Photo CD images in RGB monochrome and CMYK colors These plugging answer the demands of users for more flexibility and control in the application of Photo CD in their works Choosing the software and the method for moving from Photo CD to the computer and ultimately to the printed page is a complex path one with many options Let's examine the options and evaluate their strengths and weaknesses: Deciding which color space to use requires you to consider a number of choices and decide which is best for your production requirements There are benefits to working in RGB- CIELAB and CMYK color spaces and benefits to working in monochrome when the need is strictly black-and-white works To determine the best paths it is necessary to examine the options exclusively, since the final product of their efforts is a presentation presented on an RGB device (a monitor, digital projector, or the projection of slides). There are also benefits to the graphic artist when working in RGB. Since a sometimes-significant component of the color in an image is reduced in intensity as the conversion between color spaces takes place, some graphic arts people prefer to do their color modification work in the RGB mode before converting, preferring to see the bright RGB color in the image while making their corrections. Amazing things are afoot with new six- and seven-color printing processes, also. Called hexachromatic and hifi color printing, these advances in color printing have expanded the gamut of colors available on the printed page by producing images printed with more than the conventional four colors of the CMYK process. With these expanded ink colors, printing on paper can exceed the expectations of most viewers. Of course, printing in six or seven colors requires a more complex color separation process and a seven-color printing process, but the results are impressive. And you mu. t use RGB (or CIELAB) color space to get to these hifidelity color processes from Photo CD. Another benefit of the RGB color approach is that color saturation is often greater in an RGB image than an image that has already been converted to CMYK. Popular techniques for making CMYK separations include a process called GCR (sometimes called PCR) which reduces the density of the three primary process colors (C, M and Y) and adds their luminosity (a mathematically-derived value for lightness) to the black. The purpose of GCR is to make it easier to balance neutral colors on high speed printing presses. It can also result in some ink savings on press, though these savings do not accrue on short runs. However, when maximum GCR is applied to an image in the conversion from Photo CD (or any other original color space) to CMYK, it can leave the image lacking modifiable color. In other words, you might want to correct a color in part of the image, but might be unable to correct it because its component colors have been reduced by the GCR process. While this represents a small potential, some conversion software does not give the user the option to choose a non-GCR separation. Last, and probably the most important reason for working in RGB is for projects that are to be published not only in print, but published electronically. With the potential use of CD-ROM and Internet World Wide Web publishing, an image should be stored in RGB format, and converted to CMYK for print. This leaves the greatest number of options open to the designer, and prevents much duplicated work from being done to images with multiple purposes. When working in RGB color, it is critical to remember that viewing conditions are often different. Different monitors and lighting conditions contribute to much variation in the image seen on monitors in a variety of environments. We need to be cautious when evaluating images in each circumstance, keeping in mind that these variables can be significant. Next Colorite Home Page OPTIMIZING PHOTO CD -- MENU