基于局部估计的多光源图像颜色恒常性计算

Colour Constancy Calculation of Multi-light Source Image Based on Local Estimation

目的解决多光源场景图像的颜色矫正问题。方法首先采用网格划分和关键点取样2种方法对多光源图像划分区域,然后对划分后的区域采用单光源颜色恒常性算法估计光源,把每一个区域对场景光源颜色的贡献整合为复合光源颜色作为多光源场景的近似估计,最后采用对角模型进行矫正,并将此方法与单独用单光源颜色恒常性算法估计做对比。结果通过对多光源图像划分区域,可以弱化多个光源对图像的影响,与单独用单光源颜色恒常性算法估计对比,对图像的矫正效果显著。结论通过局部估计多光源图像,所提出的方法可以有效解决多光源室外场景图像的颜色恒常性问题。

The work aims to solve the color correction problem of multi-light scene images. First of all, mesh generation and key-point sampling were used to divide the multi-light image into a number of regions. Then, the light source of the divided region was estimated with the color constancy algorithm of a single light source. The contribution of each region made to the scene light source color was integrated as the composite light source color to be the approximate estimate of the multi-light scene. Finally, the correction was applied with the diagonal model. Such method was compared with the estimation independently made based on the single light source color constancy algorithm. The effect of multiple light sources on the image could be weakened by dividing the multi-light image into several regions. Compared with the estimation independently made based on the single light source color constancy algorithm, the correction effect of the image was significant. Through the locally estimated multi-light source image, the proposed method can effectively solve the problem of color constancy for multi-light images of outdoor scenes.