Illumination Normalization Among Multiple Remote-Sensing Images

Changes of illumination have a huge effect on image quality during imaging process. One method that compares high and low resolution images to compute MTF in image quality assessment requires images to be in the same illumination conditions. Thus, it is necessary to do illumination normalization. This letter presents a novel method by combining gradient domain method and improved singular value equalization, which can achieve a good result of illumination normalization. The gradient domain method can bring the contrasts of multiple images to the same level while the improved singular value equalization can make their intensity means close to each other. We also suggest a parameter named p to assess the illumination consistency quantitatively. Experimental results demonstrate that the proposed method has a good performance in visualization and quantitative assessment.