Improvement on histogram equalization algorithm of image imaged by cap lamp in underground mines
There are many limitations of using the regular histogram equalization algorithm to enhance im age, which is imaged by the miners cap lamp in underground mines, because the image has a large con centration of pixels in the low gray levels. Since the histogram equalization algorithm and the histogram specification algorithm have disadvantages in the process of enhancing the image with the characteristics of rising from low gray level to high gray level very fast, an improved histogram equalization algorithm is pres ented according to the theory of the histogram specification. The algorithm automatically determines the im age to be preprocessed or not. In the preprocess, the histogram is modified by the log transform, which has the function of mapping a narrow range of the low gray level in the input image into a wider range of output levels. This preprocess expands the dynamic range of the input image. Whether it is preprocessed, the im age will be histogram equalized. Theoretical analysis and experiments show that the improved algorithm ex pands input-output gray level transform function, enhances the quality of the image imaged by cap lamp in underground mines greatly, and that the preprocess log transform is implemented efficiently through the lookup and is very suitable for the real-time image processing system.
cap lamp illumination histogram equalization image enhancement log transform real-time image processing
Houqing Kang Yanqing Wu Yunbing Hu Jun Zhang Chengliang Xie Xiaoli Ma
Chongqing Branch of China Coal Research Institution, Chongqing 400037 , China
国际会议
重庆
英文
235-241
2009-05-20（万方平台首次上网日期，不代表论文的发表时间）