Research On Dehazing And Enhancement Methods For Sequence Images

With the development of economy and industrialization,the atmospheric environment becomes increasingly worser,and hazy days appear more frequently at present.And images picturing in hazy days will be easily degraded more or less.Meanwhile,some unstable factors during imaging process such as system vibration will also lead to image blurring.Image quality will be poor when the above two factors occur simultanesously.However,there are few studies on the restoration methods of degraded images considering both two factors at home and abroad.Current research is limited to single degraded factor namely image dehazing or image deblurring.In view of this situation,the following three parts of research are carried out:?1?A new degradation model of hazy and blurred image is proposed.The model is based on the atmospheric scattering model and the blurred degradation model.It considers the physical imaging process of the hazy and blurred images.This paper derives the degradation model from the hypothesis that the process of atmospheric degradation and the process of vibration causing motion blur are independent.In the process of model derivation,the corresponding mathematical approximation is made according to the specific conditions,which can simplify the calculation.The experimental results show that the model can effectively describe the degradation process of hazy and blurred image.?2?A restoration method for hazy and blurred multi-frame image is proposed.This method is based on the degradation model of hazy and blurred image proposed above.The dark channel prior is used to estimate the atmospheric light and transmittance,therefore the image restoration problem is converted to a blind deconvolution problem.A deblurring method of multi-frame image is proposed under the Bayesian posterior probability model,where the latent images are regularized by a natural image gradient prior and the point spread functions are regularized by an ₁l-norm based prior.An iteratively alternating minimization approach is used to solve the optimization problem.Experimental results of synthetic images and real world images demonstrate that the proposed method can recover images effectively.?3?An image quality enhancement system based on multi-frame image is designed and developed.The system considers comprehensively the degradation model and restoration method proposed in this paper.It can synthesise hazy and blurred image and enhance the image quality of the synthetic and real shot hazy and blurred image.