灰度一致纹理图像的光参数估算方法

Estimation of Lighting Parameters for Uniform Texture Image

从单幅图像估算光照参数时未知条件太多,而采用多幅输入图像的方法估算光照参数,虽然精度较高,但增加了输入数据的复杂度。提出灰度一致图像的光参数估算方法,能够从输入的单幅图像准确地估算光照参数。该方法通过探测输入图像的最大亮度变化方向估算光照的方位角;通过检测输入图像与虚拟光环境下的随机纹理的相似性估算光照的翘角。对Photex纹理库中的24类图像(共142幅图像)进行了实验,实验结果表明,该算法对于表面灰度一致图像的光参数估算具有较高的准确率。

Estimating lighting direction from a single input image requires too many unknown parameters, whereas although the accurate estimated lighting parameters from multiple input images can be obtained, the complexity of the input data is increased. The method for lighting parameters estimation of the uniform texture images is proposed. The proposed algorithm only utilizes one input image for estimating the lighting directions. By detecting the largest direction of the brightness changes of the input image, the azimuth angle of the light source can he estimated. The slant angle is estimated by detecting the similarity between the input image and the random texture with virtual lighting conditions. 24 kinds of texture images （142 images） in Photex database are studied experimentally. Experimental results show that the proposed approach is effective and robust in estimating the lighting parameters for the uniform texture images.