关键词: SURF特征保留, 二维网格变形, 内容感知图像重定向, 图像翘曲方法, 图像质量评估

Abstract: Image retargeting is a digital media processing technique that adjusts the image size to fit the target resolution of any display device aspect ratio.Most of the existing research on image retargeting focuses on the shape preservation of important objects,while the key features of images are sensitive to the human visual system are not fully considered,resulting in lower visual acceptance.Therefore,a new image retargeting algorithm based on explicit SURF feature preservation is proposed.Different from the general mesh deformation technology based on vertex or axis alignment,the mesh deformation technique based on mesh edge is adopted.First,an affine matrix is defined,so that each mesh edge is deformed according to the affine matrix to form a basic mesh edge-based deformation model.Then,the SURF feature region is obtained by SURF feature detection,and the mesh edge range is constrained to the SURF feature region to achieve the feature preservation effect.Thereby,a new mesh deformation mo-del is obtained.In addition,a sparse energy term is set on the basis of the basic mesh deformation model,that is,assigning initial weights to each mesh edge to make the grid lines sparse each other,thereby solving the problem of grid line self-intersection.This weight can also be updated during the iterative solution process if necessary.Finally,an image quality assessment is performed between the proposed method and two existing image retargeting methods.The proposed method can minimize the distortion and produce better visual effects during the image retargeting process.The highest score gain can reach 16.0% and 9.7%,respectively.

Key words: 2D mesh deformation, Content-aware image retargeting, Image quality assessment, Image warping method, SURF feature preservation