An efficient projection defocus algorithm based on multi-scale convolution kernel templates  

作　　者：Bo ZHU Li-jun XIE Guang-hua SONG Yao ZHENG 

机构地区：[1]School of Aeronautics and Astronautics,Zhejiang University [2]Center for Engineering and Scientific Computation,Zhejiang University

出　　处：《Journal of Zhejiang University-Science C(Computers and Electronics)》2013年第12期930-940,共11页浙江大学学报C辑（计算机与电子（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Nos.11272285,61008048,and 10876036);the Zhejiang Provincial Natural Science Foundation(No.LY12F02026);the Department of Science and Technology of Zhejiang Province(No.2009C31112),China

摘　　要：The focal problems of projection include out-of-focus projection images from the projector caused by incomplete mechanical focus and screen-door effects produced by projection pixilation. To eliminate these defects and enhance the imaging quality and clarity of projectors, a novel adaptive projection defocus algorithm is proposed based on multi-scale convolution kernel templates. This algorithm applies the improved Sobel-Tenengrad focus evaluation function to calculate the sharpness degree of intensity equalization and then constructs multi-scale defocus convolution kernels to remap and render the defocus projection image. The resulting projection defocus corrected images can eliminate out-of-focus effects and improve the sharpness of uncorrected images. Experiments show that the algorithm works quickly and robustly and that it not only effectively eliminates visual artifacts and can run on a self-designed smart projection system in real time but also significantly improves the resolution and clarity of the observer's visual perception.The focal problems of projection include out-of-focus projection images from the projector caused by incomplete mechanical focus and screen-door effects produced by projection pixilation. To eliminate these defects and enhance the imaging quality and clarity of projectors, a novel adaptive projection defocus algorithm is proposed based on multi-scale convolution kernel templates. This algorithm applies the improved Sobel-Tenengrad focus evaluation function to calculate the sharpness degree of intensity equalization and then constructs multi-scale defocus convolution kernels to remap and render the defocus projection image. The resulting projection defocus corrected images can eliminate out-of-focus effects and improve the sharpness of uncorrected images. Experiments show that the algorithm works quickly and robustly and that it not only effectively eliminates visual artifacts and can run on a self-designed smart projection system in real time but also significantly improves the resolution and clarity of the observer＇s visual perception.

关 键 词：Projection focal Sobel-Tenengrad evaluation function Projector defocus Multi-scale convolution kernels 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] O175.5[自动化与计算机技术—计算机科学与技术]