Digital Photography for Graphic Communications
Chapter 4 • Color Management
How can you get consistent color from camera to monitor to print? Shouldn’t color match by itself? The advent of desktop publishing in the 1990s enabled users to connect various “plug-and-play” color peripherals, including cameras, monitors, and printers. Although standards have helped create uniform color, one device does not necessarily “know” about the others or the way they save, show, or print color.
One standard that has helped overcome device color differences is the International Color Consortium (ICC) profile format, which characterizes devices by relating their color to a mathematical model of human vision. Colour profiling is a great solution to the quest for closely-matching color but can be a challenge to set up.
The purpose of this chapter is to help users understand the concepts behind color management. To implement a system, help will undoubtedly be required from systems and peripherals vendors.
ICC profiles capture the color reproduction characteristics of each device using an industry-standard file format for both Windows and Macintosh computers (Figure 4-1). These profiles can be read by ICC-compatible photo-editing, illustration, page-layout, web-design, and web-browsing programs as well as the drivers and raster image processors (RIPs) that control printers.
When considering workflow, keep in mind that the goals of using color management in a digital workflow are to have:
- accurate, consistent color from the original scene, photographic print, or transparency to final output (printed or displayed).
- accurate monitor previews of the original file, final output, or proof.
- proofs that simulate press sheets or production printers.
The Source-Destination-Simulation Model
The above workflow objectives are facilitated by four types of ICC profiles:
- source profile—This profile describes the color space in which the image was created or currently exists—generally a scanner or camera profile. It could also be a standard working space profile. Ideally, all images with a scanner or camera profile should be converted to a standard working space, and the standard working space profile should be embedded into files, so users can identify it down the line. If you or your customer don’t know what standard working space was used, you won’t be able to get matching color.
- standard working space profile—A standard working space is a place to store data until you know what you want to do with it (display, proof, print, or archive it). Adobe Photoshop and other applications support several standard RGB working spaces, including (from largest to smallest) Adobe RGB, ColorMatch RGB, and sRGB. Most content creators today use the largest, Adobe RGB. Users with CMYK workflows can use one of Adobe’s standard CMYK working spaces, such as U.S. Sheetfed Coated or U.S. Web Coated (SWOP). Of these Sheetfed Coated has the larger gamut, but SWOP is more common. SWOP (Specificati