The father of desktop publishing Adobe Systems Inc.

Adobe Systems Inc. was founded in 1982 and has grown into a major international organization within less than 20 years of development like Microsoft. It is now the second largest software company in the world. Well-known software products are Photoshp.Pagemaker.Illustrator and Acrobat (PDF) and so on. Adobe systems Inc. introduced Postscript page description language technology in 1985, enabling users to obtain high-resolution output. Since then, there have been a variety of images and typesetting software using Postscript technology. This has led to the successful development of desktop publishing. It has also increased the sales of Apple Computer in the 1990s, becoming the standard equipment for design and publishing.

Postscript Color Management Mode Most color management software tools correct image color before output, but Postscript's color management method is performed at output time, converting RGB colors to ideal CMYK colors. The second generation of Postscript also supports ICC color management. In addition, most color management systems commonly use CIELAB as the reference color gamut, but Postscript uses CIEXYZ as the reference color gamut. (CIEXYZ is basically the same as CIELAB. It also represents the color range of the human eye. It is the standard published by CIE in 1931 and 1976 respectively.) Postscript color management adopts the Color Space Array (CSA) and Color Rendering. The Dictionary (CRD) is relatively equal to the source profile and the output profile, respectively. Some color management systems use other names to represent sources and output profiles, and readers should be careful about this.

Postscript has three color management output mode modes (1) - in the computer platform to convert the color output driver first image color to the printer's color. Assume that the output driver supports color management (such as the Epson Stylus800 printer driver), which can call color management centers (such as ColorSync) for colorization through the source features (such as scanners) and the color characteristics provided by the printer's profile (such as inkjet printers). Convert, and then send the corrected CMYK color data to the printer for final output. This mode is suitable for output devices that do not have color management capabilities, or it is better to consider color conversion at the computer than to perform color conversion within the printer.

Mode (2) ------ Converting color within the printer must first be a Postscript output device. The output driver first transfers RGB (or other color mode) colors to an output device (such as a Postscript laser color printer), and then the source The profile is converted to a CSA Postscript color (Color Space Array), and the output profile is loaded into the CRD (Color Rendering Dictionary). The color conversion can then be performed within the output device. This mode differs from mode (1) in that the color conversion work is transferred to the output device. Then the computer can restore freedom more quickly. However, note that each CRD specifies an output device and cannot be used on other machines.

Mode (3) ------ Output device built-in profile and mode (2) are similar, but the output device itself has been installed CRD, so the driver only needs to send the image color data and source characteristics to the output machine. With source color characteristics, output color characteristics, and CIEXYZ reference color gamut, color conversion can be performed on the output device.