基于球面谐波理论的染色品色差检测光照校正

染色品色差检测是染色品质量评价的关键，照射光源的不一致将导致严重的色差评价误差。本论文将基于球面谐波理论的光照校正算法引入到染色品色差检测的光照校正中。首先将采集到的同一光源下的图像进行光照色调颜色恒常性算法校正；然后测量不同光源照射下染色品的反射率，基于球面谐波理论进行光照光谱能量估计与光照补偿；最后采用两种纺织行业最常用的色差公式CMC(2:1)和CIE1976L*a*b*对上述两种算法产生的图像处理效果进行分析。实验结果表明，本文提出的方法用于染色品色差检测的光照校正中，实现了图像在多种光源之间的相互转换，减小了由于光源不一致问题产生的色差评价误差，提高了染色品质量评价的诚信度。

Application of illumination correction to measurement of color difference of dyed products based on spherical harmonic theory

In the color difference measurement of dyed products,different illuminants will lead to serious errors in evaluation of color difference.For this reason,we introduce a new illumination correction algorithm based on spherical harmonic theory into the measurement of color difference of dyed products.Firstly,the collected images under the same light source are computed using the color constancy algorithm;then the reflectance values of the dyed products are measured under different illuminants,and the spectral energy estimation and illumination compensation are performed based on spherical harmonic theory;and finally,the two color difference evaluation formulas CMC(2:1) and CIE1976L*a*b*,commonly used in the textile industry,are adopted to analyze the image processing effects of the above two algorithms.Experimental results show that when used in illumination correction for color difference measurement,the proposed method can reduce the evaluation errors caused by inconsistent illuminations and improve the consistence of color difference evaluation of the dyed products through the mutual conversion of images between light sources.