Improved Image Enhancement for Vehicle Personal Recorder

Abstract

In this paper, we proposed an adaptive histogram stretching algorithm for preprocessing image enhancement of the vehicle personal recorder. This algorithm is suitable for image preprocessing to search car license plate. The proposed algorithm employs the Probability Density Function (PDF) and Cumulative Distribution Function (CDF), which are used to analyze the distribution diagram of the images. And the resulted image is subjected to different stretching value. Experiments have been executed on the images captured by the vehicle personal recorder, from which have been used to extract its characteristics. The images were taken in the rainy night, the underground parking lot and pass through a tunnel. The experiment results show that the proposed algorithm provides less deterioration than conventional algorithms does. Moreover, contrast is enhanced appropriately to the characteristics of the image..