A Brief Discussion On The Test Method Of Color Restoring Ability Of Inner Frame Of Matte Lamination Scanner

A brief discussion on the test method of color restoring ability of Inner Frame of Matte Lamination scanner

Most scanners have been calibrated at the factory, but due to the difference in manufacturing conditions, light source color temperature changes, old and new degree will affect the pointer of the scanner. When buying a flatbed scanner, manufacturers usually provide a standard transmission or reflection copy, including a neutral gray scale and some color blocks. After normal scanning of the standard manuscript, the RGB 3 channel pixels of a first-line image (white or black lines are particularly obvious) are observed in Photoshop6.0 to check the scanning accuracy (high magnification should be selected during observation). The non-coincidence of the corresponding pixels of RGB channel will affect the clarity of the scanned image on the one hand, and affect the color reproduction effect in the reproduction process on the other hand.

Neutral gray scale was used to test the flatbed scanner's ability to restore neutral gray color and the performance of the scale's density level change. The correct restoration of neutral gray color by scanner is the premise and foundation of color recognition and color restoration. Scanning color bias is generated in the process of scanning due to the difference between the color sensing performance of scanning components and standard components. Although the scanner has been calibrated before leaving the factory, some color bias is inevitable in use. In the actual process, the display screen is usually corrected to make it display the color correctly, and then the scanning color bias is corrected.

At present, the prepress part of the production center uses a high file scanner, the software can mostly customize the output feature file, such as Heidelberg scanning software NewColor can define the RGB output feature culture. As long as the output properties file in the scanning software is set to the same as the "RGB Settings" in PhotoShop, so that the image in PhotoShop and NewColor screen display is close to the same. For lower-order scanners, scanning feature files is not supported and PhotoShop features can be used.

When correcting scanning color bias, the scanned neutral gray scale was placed in Photoshop6.0 image processing software, and the RGB values of each level of the scale in the image were displayed using the information modulation board. Then the Curves were called to adjust the RGB channels until the CMYK values of each step in the image reached the required value of neutral gray. At the same time, the neutral gray scale can be visually observed on the display screen. The Curves in this case are the color curves generated by the scanner after color bias correction. When scanning images, you should properly compensate the colors based on the curves. The curves can be saved for easy use. By scanning the color blocks in the standard manuscript, we can judge the reproduction characteristics of each color by the scanner. The visual contrast between the original manuscript color block and the scanned image can qualitatively understand which colors are better reproduced by the scanner and which colors are worse, so as to facilitate the correction of colors with poor reproducibility by image processing software in the future in the scanned image. In addition, the scanner should be corrected regularly.