Research On The Restoration And Processing Technology Of Spatial Defocused Blurred Image

The defocused blur caused by the improper focus of the detector optics system is the most common blurred form for the spatial image. Defocused blur means that the subject is not in focus position, and with the greater distance between the target and focus, the image will become more blurred. Defocused blur will cause the loss of high-frequency part of the image and the blur of the image, so Defocused image cannot be directly applied in space science research. Therefore, the clarity of the defocused image is of great significance for the development of space-based space technology.In this paper, according to characteristics of the defocused blurred image, we mainly do the following research aspects:1) For the image preprocessing, this paper presents a wavelet domaindenoising method, namely the improved iterative bayesshrink thresholdestimation + Wiener Filter. Experiments show that this method is betterthan the traditional image denoising methods in the denoisingpreprocessing filed.2) For disc defocus model, this paper presents three new and improved methodof defocused blurred radius estimation: estimation based on SVM,improved differential autocorrelation methods and in-focus degree methods.Experimental results show that these methods, under certain circumstances,can be very good to estimate the blur radius.3) For image restoration methods, on the basis of the traditional imagerestoration, this paper proposes two improved image restoration methods:improved inverse filter method and improved Wiener filter method.Experiments show that these two methods can be more effective to restorethe blurred image.4) For the evaluation of image restoration effect, this paper proposes a gradientedge operator to evaluate the image, and the experiment shows that theevaluation function is effective and reasonable.At the end of this paper, the proposed defocused blurred restoration processing technology verifies by experiments, the results show that the proposed method can effectively restore defocused blurred images.