ColorSync: Управление цветом в macOS

ColorSync is Apple Inc.'s color management API for the Mac OS and Mac OS X Operating Systems.

Apple developed the original 1.0 version of ColorSync as a Mac only architecture, which made it into an operating system release in 1993. In the same year, Apple co founded the International Color Consortium (ICC) to develop a cross platform profile format which became part of ColorSync 2.0. The system Color Management Module (CMM) was "LinoColorCMM", which was developed by Linotype Hell AG (now part of Heidelberger Druckmaschinen AG). The same CMM was used in Microsoft Windows 2000 and XP under the rubric of "Image Color Management" (ICM). Apple, with the help of Adobe had ported ColorSync 2.0 and its SDK to Microsoft Windows. With ColorSync 3.0, the Windows version which was initially planned was discontinued. ColorSync 4.0 is the latest version, introduced in Mac OS X 10.1.

Human color perception is a very complex and subtle process, and different devices have widely different color gamuts or ranges of color they can display. To deal with these issues, ColorSync provides several different methods of doing color matching. For instance, perceptual matching tries to preserve as closely as possible the relative relationships between colors, even if all the colors must be systematically distorted in order to get them to fit within the gamut of the destination device. Because the human eye is more sensitive to color differences rather than absolute colors, this method tends to produce the best looking results, subjectively speaking, for many common uses, but there are other methods that work better in some cases.

As dictated by the ICC system, the profile connection space in ColorSync is the CIE XYZ color space. All image input and output devices (scanners, printers, displays) have to be characterized by providing an ICC profile that defines how their color information is to be interpreted relative to this reference color space. This profile might be provided by the device manufacturer, but for better quality results, it might be generated by performing actual measurements on the device with a colorimeter. Thus, when an image is scanned on a scanner, the image file will include a copy of the scanner's profile to characterize the meaning of its color information. Then, before the image is sent to an output device, a matching process converts the color information at the time of rendering from the source profile (that attached to the image) to the destination profile (that attached to the output device) so that the resulting colors print or display as closely as possible to the original image.