I would like to write some of the color management process experiments that I have done in the past two days. I hope to help everyone better understand the concept and process of color management. We will not talk about empty theory and only do actual operations!
First introduce my experimental tools and software: color management tool software: profilemaker5, this software is used to measure and generate equipment (scanners, digital cameras, monitors, printers, etc.) ICC color profile, and can do some Color comparison and feature file editing; standard color target: Grinder Digital ColorChecker SG; color management system software: PHOTOSHOP, note that I do not use a variety of popular color management software such as: EFI, GMG, etc. because I I hope that everyone can truly start with the basics of color management, understand more deeply some basic concepts in color management, and make good use of Photoshop's powerful color management functions; measuring instruments: spectrophotometer: EYE ONE; display: EIZO civilians L768, useless professional CG220 is to let everyone not too superstitious equipment, as long as it is not deviating from the standard too outrageous equipment, we can let color management work well; Printer: EPSON A3 format R1800, large format 9800 , A total of two; printer driver: EPSON original driver.
The purpose of the experiment: Focusing on PHOTOSHOP color management software, the true color can be accurately collected and restored, and the input devices, display devices, and various output (printing devices) can be harmonized with each other to realize the true meaning and process of color management.
The first step in color management: how to get real or near-real colors?
One: Establish a profile of an image acquisition device (scanner or digital camera)
In this example, I used the Digital ColorChecker SG, a standard color target from Gelinger, as an illustration.
The color target was originally used to make a digital camera's characteristic file, because the digital camera is greatly affected by ambient light, so I use a platform scanner as an input device to collect the standard color on the color target.
Now we first set the scanner back to the default state and turn off the color part of the scanner. Here we don't care if your scanner doesn't support color management. In this experiment we must turn them off. We all let PHOTOSHOP come. Finish color management work, in addition, when doing ICC also need to get the scanner's raw data!
Scan the Digital ColorChecker SG color target and save it as a TIFF file: 11.58.tif, and then open profilemaker5 to use the scanner's module to generate the scanner's profile.
Two: The conversion gets the true color:
Then open the scanned 11.58.tif in PHOTOSHOP, click on the menu "Edit" in the "Assigned configuration file", this step is to tell the system the source of this map is what space? What is a "source profile" or "input profile" in a color management system?
Then we need to convert the picture again. Why? Because our goal is to collect real colors through the color management system! So now we convert the space of the graph into the color space of the LAB and see if the Lab color of the resulting patch color is the same as the standard color of this Digital ColorChecker SG target.
The source space is the scanner's characteristic file sgsaomiao 4.icc. We converted it to Lab space. The intention must be absolute color comparison. Because the Lab space is larger than any space, there will be no loss of conversion. After the conversion, we will Save it.
In fact, after the completion of this step, as long as your monitor is calibrated, then the system is also completed this picture on the display of the real display you can compare the display and the actual color of the difference! Is it big? I believe it must be a very small difference. This difference comes from two aspects: 1. The color space in the object exceeds the color space of the scanner, so the color difference is generated (we can analyze the actual color difference by PM5). 2. The color space of the monitor is smaller than that of the scanner. The color space again produces a certain color difference.