Research On Artifact-free Multi-image Mosaic Algorithm Based On Super Pixel

With the rapid development of computer vision technology,image stitching algorithms have been gradually applied to all aspects of our lives.Technical applications of stitching algorithms can be seen in map software,playgrounds,medical technology,and security fields.However,the registration of complex scenes,random camera movements,and artifacts caused by various reasons have always been difficult points in the research of image stitching algorithms.This article addresses the above issues from The two steps of registration and synthesis of image stitching are improved.The main research contents and innovations are as follows:(1)The projection parameters for homography will cause perspective distortion,which is not conducive to multi-image splicing;spherical projection mapping algorithms have strict requirements on the movement of the camera;algorithms that use grids as the registration unit ignore the content of the scene in the image,The same object uses different mapping parameters and other issues.This paper proposes a multi-image registration algorithm based on super-pixel units.The super-pixel is used as the registration unit,and the local mapping matrix of each super-pixel unit is solved according to the interior points obtained by RANSAC.Then use RANSAC to filter the purer points and solve the global similarity transformation of each input image.Constructs an adaptive nonlinear transformation function for each image,which makes a good transition combination between the local homography matrix of the superpixel and the similar transformation.each image is subjected to motion transformation relative to the reference image,and finally the result of pre-registration is obtained.It can perform better pre-registration of the camera’s translational movement,rotation movement,and more complex movements.(2)Aiming at the small artifacts that may be generated by the registration,the stitching algorithm of dynamic programming is improved,and a small artifact removal algorithm based on greedy search is proposed.Establish the path search model between the endpoints,and combine the gamma transformation to improve the distance transformation step to obtain the Dmatrix matrix.And then combined with the classic cost function to generate the cost matrix Ematrix,and finally the greedy search step of the stitches is given.Using this algorithm to compare with traditional dynamic programming algorithms can effectively remove small artifacts,and the effect is better than traditional algorithms.(3)Aiming at the large artifacts that may be generated by the registration,the traditional graph cut optimization stitching algorithm is improved,and a large artifact removal algorithm based on superpixels is proposed.Taking superpixels as the unit and considering the color differences of superpixels,six layers Color model,obtain the color difference cost function,consider the structural difference of super pixels,obtain the gradient direction histogram of each super pixel,construct the structure cost function,and introduce the cost function of super pixel entropy as the adjustment between color and structure Coefficients,finally,construct a new target energy function,treat each super-pixel block as a node of the graph,establish a graph model,and use the maximum flow algorithm to solve it.Get sutures.Compared with the traditional graph cut algorithm,the effect is better than the traditional algorithm.In summary,this article presents the processing flow of the artifact-free multi-image stitching algorithm based on superpixels,and selects images from multiple scenes for stitching experiments,and compares them with other algorithms to verify the processing artifacts of our algorithm in different scenarios.The effect of shadow is better than other algorithms.