Clear color correction concepts and methods (1)

Whether it is the use of high-end electrical networking extensions or desktop systems for color image processing, one of its key technologies is to make correct color corrections. The purpose of the first is that the customer requests the color of the original document and corrects the color of the original document. Secondly, the customer requests the improvement of the defects of the original color, and the color correction is performed to meet the requirements of the customer. Third, the color of the original document is required to meet the requirements of the user. Color, color correction in order to meet people's appreciation of the heart. Ultimately achieve customer and reader satisfaction.

In the current color prepress image processing operations, how to do color correction, there are three kinds of fuzzy concepts and unclear operating methods, first, the technical work of reducing the technical and processing of the original color defect concept is unclear, resulting in should Reductive work is not done well. It should deal with the defects of the original color and it is not handled well. Second, the concept of the function range of subcurve and color correction tools is unclear, and there is no specific application, resulting in achromatic and color. Interference; Third, the relationship between the color of the selected correction and the color of the same color is unclear, resulting in correction of a certain color gamut, and also implicating the hue of the same color system, causing color confusion. Due to the above problems in color correction, in actual production, the original color cannot be properly restored, and defects of the original color cannot be handled properly, thus resulting in poor image color effect and dissatisfied customers and rework again and again. Therefore, the color separation of the current color prepress system and the color correction of image processing should be changed from "fuzzy concept to rationalization" as soon as possible, and the correct color correction method should be mastered. Only when the concept is clear can the purpose of the work be clearly defined. Only when the method is correct can detours be avoided. Received a multiplier effect.

Three concepts of a clear color correction

1. Correcting the original color correction

The correct reproduction of manuscripts is the basis of reproduction. It is also the requirement for most artists and photographers to copy paintings and photographs. Therefore, in order to restore the original color, color correction is required. This correction mainly corrects the color error caused by color decomposition, color transfer, and color combination in the copying process. E.g:

1. Correct the color filter error. Due to the transmittance of the color filter and the performance of the absorption spectrum, the color separation effect of the direct shadow color, there is no absorption that should be completely absorbed, and there is no penetration that should be completely transmitted, resulting in a color separation error. The commonly used Kodak-Leden filter R25 has transmittance of 89.5%, G58, transmittance of 53.6%, 47B, and transmittance of only 50%.

As shown in Table 1, 2 and 3

The ideal filter transmittance is shown in Table 2.

Actual maximum transmission rate is Table 3

This indicates that the M color plate of the color separation of the G58 filter and the Y color plate of the color separation of the 47B color have a large color error, which requires correction.