Study On Image Deformation Based On Moving Least Squares

Image deformation is an image processing technique, which creates smooth and realistic deformation results based on deformation control features and definite deformation functions. This technique is widely used in virtual reality, computer animation, medical image processing and movie & TV field.A point-based image deformation method using moving least squares(MLS) is studied. First, point-based MLS mathematic model is analyzed and the feature control points are set according to deformation requirement. The point-based transformation functions are studied to compute afflne, similarity and rigid deformations of image and obtain image deformation results by moving control points. Then comparison of affine, similarity and rigid image deformation results is made.Based on the research above, a MLS image deformation method using control curves is studied. According to shape information or deformation requirement, key points are set to create cubic-spline curves. The curves are moved to new positions to control the deformation of image. Then the transformation functions based on control curves are deduced to compute affine, similarity and rigid deformations of image and realize realistic image deformation results.To keep the real time of image deformation, an accelerated algorithm of curve-based image deformation is implemented by OpenGL texture mapping. The original image is partitioned by grid and the deformed coordinates of every grid vertex are computed. Then deformed image framework is created in OpenGL; 2D image before deformation is translated into texture and mapped to the deformed image framework, which accelerates time cost and realizes the real time of image deformation.A system of image deformation has been exploited based on the above-mentioned methods. It can realize MLS image deformation based on points, curves and grid vertices. Every deformation method concludes affine, similarity and rigid deformations of image. The experimental results show that the system has visual operation interface and makes the operation convenient for users.