Research On Blind Restoration Of OCT Image Based On Improved NAS-RIF

Optical coherence tomography uses low coherence of the light source to obtain the internal structure of measured sample,which is widely used in the fields of biomedicine,clinical medicine and nondestructive testing of objects.However,in the imaging process of OCT system,degradation occurs due to CCD integral effect and noise.Such degradation will not prevent the clear image with small structure and low intensity tissue,which directly affects the accuracy of image analysis.The nonnegativity and support recursive inverse filtering of the blind restoration method can retrieve valuable image information from degraded images However,when restoring images,the existing NAS-RIF method and its improved method are easily affected by the noise of the observed image,which make the deviation of the estimated image,and not take into account the details of the image at the same time,restricting the improvement of image quality.In this case,studying the blind restoration of OCT images based on the improved NAS-RIF to obtain high ratio of signal to noise OCT images with clear structure and edge has great theoretical significance and application value.Based on the analysis of OCT image restoration method and the effect of noise on NAS-RIF method image quality of blind restoration,a blind OCT image restoration method based on the improved NAS-RIF is proposed in this paper.Firstly,the geometric nonlinear diffusion filter was used to screen out the partial noise of the image,and the support domain of the OCT image was estimated by using the minimum error threshold method based on Poisson distribution.Then,the total variation of the estimated image was introduced into the cost function,and an improved generation of the regularization term based on the anisotropic total variation(ATV)was constructed by regularization technique.The split Bregman iteration method is adopted to construct the optimal solution strategy for the image restoration optimization.The proposed method is tested by both Plane image and Camera image and the OCT images.The experimental results show that the proposed method of blind restoration of OCT image based on improved NAS-RIF are able to achieve the blind restoration of the noisy OCT image with good robustness,improve the noise ratio signal of the OCT image,at the same time retained the details of the image.The method also obtain the OCT image with clear structure and obvious edge of the sample,which provides an important basis for the accuracy of scientific research and the correctness of the clinical study.