US 11,928,842 B2
Method and apparatus for measuring chromaticity of a target object
Hsiang-Chen Wang, Minsyong Township, Chiayi County (TW); Yu-Ming Tsao, Minsyong Township, Chiayi County (TW); and Yu-Lin Liu, Minsyong Township, Chiayi County (TW)
Assigned to National Chung Cheng University, Chiayi County (TW)
Filed by NATIONAL CHUNG CHENG UNIVERSITY, Minsyong Township, Chiayi County (TW)
Filed on Apr. 26, 2022, as Appl. No. 17/729,228.
Claims priority of application No. 110142801 (TW), filed on Nov. 17, 2021.
Prior Publication US 2023/0154049 A1, May 18, 2023
Int. Cl. G06T 7/90 (2017.01); G06F 17/18 (2006.01)
CPC G06T 7/90 (2017.01) [G06F 17/18 (2013.01); G06T 2207/10024 (2013.01); G06T 2207/10036 (2013.01); G06T 2207/20081 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of measuring chromaticity of a target object, the method being implemented using an apparatus that includes a processor and that stores a plurality of light source spectrum datasets each associated with a specific object, and comprising steps of:
A) obtaining a captured color image of the target object;
B) generating a spectral image based on the captured color image using a spectral transformation matrix;
C) obtaining one of the plurality of light source spectrum datasets that is associated with the target object; and
D) calculating a chromaticity dataset of the target object based on the spectral image and the one of the plurality of light source spectrum datasets;
wherein step D) includes sub-steps of:
D1) for each of a plurality of pixels contained in the spectral image, obtaining a set of tristimulus values using a plurality of color matching functions of the CIE 1931 XYZ color space; and
D2) calculating the chromaticity dataset of the target object based on the sets of tri stimulus values respectively obtained for the pixels contained in the spectral image.