A method for correcting color chromatic aberration in large format scanning based on complex spectral chromaticity theory

Abstract

The invention relates to a large breadth scanning color aberration correcting method based on a complex frequency spectrum chrominance principle, and provides a method for effectively correcting large breadth scanning color aberration. The large breadth scanning color aberration correcting method based on the complex frequency spectrum chrominance principle comprises the steps of firstly, obtaining spectral reflectance of color lumps of a reflecting type scanner correcting guide list through measurement, calculating complex frequency spectrum HLS values of all the color lumps, establishing a corresponding relation of a color value RGB and the complex frequency spectrum HLS of the same color lump, scanning the reflecting type scanner correcting guide list by using a large breadth scanner, obtaining the actual scanning color information R'G'B' of each color lump of the reflecting type scanner correcting guide list through the large breadth scanner, calculating complex frequency spectrum color characteristic values H'L'S' according to the corresponding relations, correcting colors according to the differences between the complex frequency spectrum values HLS and the complex frequency spectrum color characteristic values H'L'S' to obtain the complex frequency spectrum H''L''S'' values after the correction of the large breadth scanner, and obtaining color values R''G''B'' corrected and output through the complex frequency spectrum H''L''S'' are corrected, namely, the color values R''G''B'' are the color values of large breadth scanning colors.

Description

technical field [0001] The invention relates to the technical field of printing, in particular to a method for correcting color chromatic aberration of large-format scanning based on complex spectrum chromaticity theory. Background technique [0002] The linear array CCD used in large-format scanning uses color filters to obtain the RGB three-color information of the scanned image. The color information obtained in this way can only reflect the reflection of the spectral bands transmitted by the three color filters of the scanned object, and cannot The spectral reflectance information of the entire visible spectrum cannot be well reflected, so during the scanning process, it is easy to have a deviation between the scanned color and the real color, and the scanned color needs to be corrected. [0003] At present, the calibration of scanned colors at home and abroad is to establish the corresponding relationship between the real color and the scanned color through the CIELab c...

AI Technical Summary

Problems solved by technology

[0002] The linear array CCD used in large-format scanning uses color filters to obtain the RGB three-color information of the scanned image. The color information obtained in this way can only reflect the reflection of the spectral bands transmitted by the three color filters of the scanned object, and cannot It cannot reflect the spectral reflectance information of the entire visible spectrum well, so it is easy to have a deviation between the scanned color and the real color during the scanning process, and the scanned color needs to be corrected

[0003] At present, the calibration of scanned colors at home and abroad is to establish the corresponding relationship between the real color and the scanned color through the CIELab chromaticity space, and the CIELab chromaticity value is based on the human visual matching experiment results: CIE1931 standard chromaticity observer spectrum On the tristimulus value, calculated on this basis, cannot reflect the pure physical color information of the object

At present, the CIELab chromaticity space used in the color correction of large-format scanning has more human factors in it, and the correction effect is not ideal. It is often necessary to manually correct the scanned image in the later stage.

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