Research On Laser Spot Image Restoration Method Of Non-uniform Array Target

The measurement of the energy distribution of the far-field laser facula with the array target is a direct measurement method.Because the distribution of the detectors on the array target is not uniform,the collected facula signals are discrete and non-uniform.The gray value of the initial facula image obtained by the arrangement of the detectors on the target surface and the analysis of the facula signal is also non-uniformly distributed,so it is necessary to use an image interpolation algorithm to restore it.Based on the study of traditional image interpolation restoration algorithms,this paper proposes an array facula image interpolation algorithm based on the predicted diffusion gradient,the algorithm first calculates the gradient value in each direction of the image,and then performs diffusion processing on the gradient value in each direction in the low-resolution image,then the Kriging method is used to predict the gradient value after diffusion in each direction in the high-resolution image,and finally,according to the gradient value after the diffusion in the high-resolution image,it is obtained whether the point to be interpolated in the high-resolution image is an edge pixel point or a nonedge pixel point.For non-edge pixels,a two-dimensional non-directional algorithm is used for interpolation,while for edge pixels,a one-dimensional directional interpolation is used.Finally,through the experiment of processing the initial facula image with the array facula image interpolation algorithm based on the predicted diffusion gradient and the classical interpolation restoration algorithm respectively,it is concluded that the algorithm in this paper has a better effect on the facula image restoration,but it takes a long time.According to the algorithms of image binarization,boundary tracking and ellipse fitting,the restored image is further processed,the facula parameters such as the facula profile and the facula diameter are determined,and the beam divergence angle of the laser is calculated.Finally,using the array facula image interpolation algorithm based on the predicted diffusion gradient and the classic image algorithm proposed in this paper to restore the initial facula image respectively,by calculating the beam divergence angle of the laser,it is found that the error between the result of the algorithm in this paper and the real value is the smallest,thus indirectly It is verified that the interpolation accuracy of the facula image of the algorithm in this paper meets the expected measurement accuracy.