Biaxial Streching Method Of Fog Image Research

Aiming at some defects which exist in a kind of algorithm on fog image sharpening at present, for instance, disposing images needs a lot of time, excessive enhancement and other phenomena may appear in disposed images, in this thesis, we come up with a kind of modified algorithm on fog image sharpening on account of movable platen.First of all, from the two aspects----image enhancement and model recovery, the thesis introduces the domestic and overseas current situation of development and application on fog image sharpening, then it discusses the physical factors of the fog image degradation phenomenon in detail, among the factors, the effect of atmospheric scattering is the most important, we make analyses from two patterns----incident light attenuation and airglow imaging. Next, we put forward the attenuation law of fog degraded image contrast.The fog image sharpening algorithm which was put forward by predecessors succeeded in making part information of depth of field suited through the way of movable platen.Thus, we can obtain clearer fog degraded images. This algorithm also has some defects inevitably, for exzample, disposing images needs a lot of time, excessive enhancement and other phenomena may appear in disposed images. In accordance with the defects we have mentioned before, based on the predecessors'algorithm, the thesis mainly research a solution which has pertinence. First, in the process of concrete operations, we need make the two courses---- the judgement on the area of sky and the process of histogram equalization for movable platen apart, we should separate the area of sky first, we must ensure that there is no point belonging to the area of sky in the formwork, then we can operate histogram equalization. Second, we amplify the step length of the movable platen.In this thesis, in order to vertify the effectiveness of the modified algorithm, we have conducted lots of experiments on MATLAB table, based on the experimental result, we can see that the modified algorithm can not only improve the clearness degree of the image, but disposing image spends less time.