The evolution of color

In the past decade, color management has a long way to go.

Color management technology has changed a lot. It was not until the mid-19th century that there was a common format for transferring color characteristics between different programs. The ICC/ICM file format is a standard way of transferring color information between the Mac and Windows operating systems. There are fundamental differences between the architecture of the Mac and the PC. Windows ICM 2 relies on individual devices to load a file on a separate control channel, while the Macintosh platform uses a control channel to assign ICC files to all devices. Although both platforms are continuously advancing and developing, there is no platform to store the support methods and applications initially hoped for. Software giants such as Adobe or Quark use parts of each technology, but they do not rely on Colorsync or ICM for conversion. So far, this is still an evolving technology.

Color information exchange is constantly improving

The situation may not be as bad as it seems. Adobe's Photoshop 7, InDesign 2 and Illustrator 10 all use a common color configuration format, which has greatly improved over the previous version and can support color management and ICC profile identification. Adobe offers a range of applications to simplify and coordinate the exchange of color information.

QuarkXPress's color management window (Edit> Preferences> Color Management) offers a different approach to management. With Quark software, you can choose to convert only objects and images in the RGB format without converting the CMYK format, and you must specify which ICC profile the monitor uses. Adobe’s products are automatically recognizable. After the 5th release, Quark experienced some color failures, but it didn't happen very often. If you use non-TIFF PICT or JPG files, each file will be separated in different ways. It still uses the CMYK output device as the final output tool.

With RGB composite printing technology, designers can use Epson inkjet printing equipment to print images via Quark 5 without Rip processing. InDesign 2 also supports RGB composite printing, and uses the specified ICC profile for each object.

Built-in RIP

The RIP tool offers more options for optimizing color output. While earlier versions did not provide full color correction and conversion support, many manufacturers today support most color management devices such as X-rite or GretagMacbeth. Features such as channel ink control, linearization, and total ink volume limitations are all necessary tools for optimizing ink distribution. In addition, RIP tools now also have the ability to switch between RGB and CMYK formats.

More refined RIP tools can also provide or specify separate ICC profiles for image and vector objects for various color modes, use reference files for proofing, and select specific usage categories for each image. Even with the above functions, some RIPs still do not recognize the built-in ICC profile, nor do they have the CMM option.

Scanners and cameras

Most scanner software supports ICC files, but not all. In general, cameras that support scanning capabilities support ICC profiles very well, while other non-professional cameras are difficult to handle. The establishment of a camera profile is the most difficult and confusing part of color management. There are already a lot of features to choose from, from objects and software programs to creating camera profiles. The biggest challenge for scanner and camera file creation is correct calibration of the device before it is created. This is the most complicated and difficult part. The goal is to create an ICC profile that can be used for different light and exposure parameters. Color Corp.'s camera profile creation software, ColorEyes, provides a fairly detailed way to create a very useful camera profile.

Color display

In the display area, Sony has introduced an auto-calibrated “smart display” equipped with a company-owned colorimeter. The function of this monitor is very exciting. It can not only adjust the RGB value for a target white point, but also can calibrate the shadow part. As far as I know, any other monitor package does not have this feature. The initial calibration cycle takes about ten minutes because the reflection of ambient light on the screen is measured in turn. If there is too much ambient light reflected on the screen, the software will give an error message.

Another exciting product is the ICS BasICColor Display 2, which supports DDC/2 information transfer between the display and the adaptive display. Basically, any monitor produced in the past three years has this function. DDC/2 allows BasICColor to control a regular computer monitor. With this option, BasICColor can automatically set the contrast, brightness, RGB values, and video card gamma correction. In essence, the display has been changed from "dumb" to "smart" display while maintaining investment.

Related education and training are increasing!

A new book on color management emerged in the new year market - "Real World Color Management" was co-published by Bruce Frasier, Chris Murphy and Fred Bunting. Peach Pit Publishing's Real World series will provide a wealth of information and answers to questions. The GATF (Graphic Arts Technical Foundation) launched the GATF Practical Guide to Color Management (GATF), which focuses on the science technology behind the color management and the outline of the current feature package. Applications such as Chromix's ColorThink and ICCTools' IccToolBox can draw ICC profiles that match the full color gamut. ColorThink has the function of dividing the color data of an image into 3D L*A*B*, and visually represents the process of converting colors into the printer's color space. By choosing different uses, you can observe which color conversion is distorted and how much it is distorted.

ICCtoolBox can demonstrate the calibration curve in two dimensions simply by the color information. This helps to identify if the paper is transitioning to ink, causing shifts in shaded areas and chromaticity on color samples.

Looking to the future

It is true that the ICC parameters specification is not perfect. The research and development carried out in the field of color science are constantly introducing revised versions. The current version has solved some obvious problems and determined the ISO-compliant file format.

One of the more challenging aspects of color reaction prediction is to observe how people perceive color under a light source. Some surveys have found that specific ink and paper combinations change under different light sources. Observers have found that when a print is in a different light source environment (such as tungsten light and fluorescent light), the color will change significantly. Both GretagMacbeth ProfileMaker 4 and BasICColor Print have the ability to capture spectral data and reset it for a specific light source. This option is very useful because prints are rarely observed under the D50 light source. More importantly, most printed light source stations do not and cannot simulate the D50 spectral energy, preferring a 5000K white point light source.

Since the 1990s, we have experienced a long period of development. At present, many major printing application software and tools have actually supported and applied ICC profiles. However, not all applications have the same features or support for ICC profiles. These softwares are still cumbersome. Color management still has a long way to go, but we have found the right direction.