Method for conversion from CIELAB color system to Munsell color sequence system

Abstract

The invention provides a method for conversion from a CIELAB color system to a Munsell color sequence system. The method is characterized by comprising the following steps of obtaining a target CIELAB color P, utilizing a linear interpolation to calculate a Munsell lightness value VP, judging the lightness face where the color P is located in a Munsell space, and utilizing a lightness face based linear interpolation to calculate a Munsell tonal value HP and a Munsell chromaticity value CP. By mans of the method for conversion from the CIELAB color system to the Munsell color sequence system, color conversion errors are decreased, and color conversion accuracy can be improved.

Description

technical field [0001] The invention relates to a conversion method from a CIELAB color system to a Munsell color sequence system, and belongs to the technical field of computer image processing. Background technique [0002] The CIE1976 standard color system, also known as the CIELAB color space, is a visually uniform color space introduced by the International Commission on Illumination (CIE) in 1976. It is derived from the CIE1931 standard chromaticity system through nonlinear changes. The CIELAB color space is represented by a three-dimensional space coordinate system, as shown in the attached figure 1 shown. The CIELAB color space is independent of various color rendering devices, and can establish contact with device-related color spaces (such as RGB, CMYK, etc.) through corresponding conversion models. Therefore, it is recommended by CIE as an intermediate connection color space for color conversion. Deals with the most important and commonly used color systems in t...

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Problems solved by technology

The shortcomings of this method are: 1. The interpolation sample points selected from the perspective of CIELAB color difference are not ideal samples, this is because Munsell colors are not regularly arranged in CIELAB color space, and CIELAB color difference is small The corresponding Munsell coordinates of the two Munsell samples are not necessarily similar; 2. The change relationship between the Munsell color scale value and the CIELAB color value on the different Munsell lightness planes is not consistent, and the method from the whole Munsell Searching for interpolation sample points within the range of the Searle space, the selected interpolation samples are not completely on the same Munsell lightness surface, so the interpolation results are also affected

Therefore, the calculation results of the algorithm used in this paper are not very accurate. According to the paper, the maximum error between the calculated color Munsell hue and the real hue reaches 26, which is almost unacceptable.

And the calculation of the corresponding Munsell lightness value and Munsell chroma value is not mentioned in the paper, which also limits the promotion and application of this method

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