The Research And Applicaiton Of Image Mattin Based On Closed-Form Solution

With matting technology widely used in image and video processing, it has get more and more attention in recent years, and new closed-form solution matting technology has become a hot issue in matting area; we will apply automatical matting techology applied to daily image and video processing, to get rid of the tedious work of hand matting, and make the image matting more convient, fast and easy to use. But there are still a lot of problems in matting, such as high-resolution image matting, matting interactive constraints,the accuracy of the result and time-complexity, etc.This thesis first reviews the development of image mating, from simplie blue screen matting to complex natural image matting and environment matting; after detailed analysis and comparison of the advantages and disadvantage of image matting, the main matting algorithm use color sampling and propagation distance method, but the propagation distance is superior.This thesis will improve closed-form matting in three aspects:First, improving local linear model, to further eliminate local nonlinear models which brings the propagated errors in alpha value. The Levin closed-form matting using a fixed-size window, and assuming a linear distribution when the window is satisfied, but the image region with blur boundary doesn’t satisfy the linear distribution, elimination nonlinearity can be able to get a more accurate alpha values.Second, in order to further increase the propagated color, the improved closed-form matting adds two virtual nodes ΩB and ΩF, this data model like Boykov graph cut module, ecach pixel in the unknow region needs to caculate similarity cost with two virtual nodes. In the calculation of Matting matrix L, by adding two virtual pixel is equivalent to increasing regional similarity cost, in process of solving alpha, it will passed known alpha value makred by brush to the unknown region of the pixel.Third, the thesis introduce a layered way in solving alpha, and compared to the singal step solver, layered solution can reduce the transmission of color interference; And the alpha value marked by foreground and background brush is passed to unknown area, when the sparse known regional alpha value also pass into the unknown region, layered solution can determine the optimal alpha value.Finally, the proposed algorithm results will compare with other matting algorithm, and anlysize the result, with other matting algorithm comparison analysis of experimental results; matting was used in building woodcut texture library and segmentation.