关键词: 低对比度, 局部灰度熵, 邻域窗口, 人体检测, 检测率, 虚警率

Abstract: With regard to the two main factors that cause the difficulty of human-detection under the dim contrast environment, a concept of the local gray entropy was introduced, and then an algorithm of human target detection based on local gray entropy was proposed for the reason that the local gray entropy could reflect the discrete level accurately, and it was independent on the average gray. After the background model was established, the local gray entropy difference between the moving objects and background model inside the domain windows was calculated by using calculation formula of local gray entropy simplified through Taylor expansion. And the ratio of detection and the ratio of false-alarm of the algorithm were evaluated. The optimal thresholds on the differential of the local gray entropy which could get the human body under the two conditions of low contrast were obtained. The experimental results show that the algorithm of human target detection based on the trait of the local gray entropy can obtain the moving human targets effectively under the dim contrast environment.

Key words: dim contrast, local gray entropy, domain window, human detection, detection ratio, false-alarm ratio