Design of a Novel Micro-detection System Based on Image Dynamic Range Enhancement

摘要

In the microscopic image detection, the image quality is the key factors for accuracy of measurement. Owing to the different material and uneven surface of work pieces, different regions of the work piece have a different response to light intensity in imaging. In order to obtain complete information of detection of objects, it is necessary to expand the dynamic range of microscopic images. A new design of micro-detection system based on high dynamic range imaging technology is proposed. The hardware of our system mainly includes computer system, light intensity control system and micro-imaging system equipped with a digital CCD image sensor. The effective synthesis algorithm for high dynamic range image based the quantity of information of image is also proposed. In our algorithm, the images are divided into to many layers levels by the laplacian pyramid algorithm and the weight of each layer is determined according to the grads and entropy of image, then the laplacian pyramid inverse algorithm is applied to obtain a high dynamic range image. The detail features in both areas with high and low illumination of the view can be increased. The experiments have shown that the entropy and definition of composite image is better than each images of different exposure. Therefore, the method we propose can effectively improve the resolution of the microscopic images and the accuracy of detection.