非局部特征方向图像插值方法研究

摘要

提出了一种非局部的特征方向图像插值方法，有效地保持了插值图像轮廓的光滑，抑制了图像边缘的模糊。这种方法把非局部 Hessian 矩阵的特征向量视为图像特征方向，使图像能量泛函沿这个方向进行扩散，其扩散强度由图像局部 Hessian 矩阵特征值参与控制。它克服了传统方法以梯度方向指示图像特征方向的局部性，使图像能量泛函沿正确方向扩散，避免了对图像特征的模糊。数值实验结果显示，该方法既能很好地重建插值图像的边缘，又不会在插值图像中产生伪影或图像边缘失真。%A method of image interpolation with non-local feature directions is proposed.This method respectes the smooth of the contour profile of interpolated image and retrains blur edges.The eigenvector of the non-local Hessian matrix is considered as the image featrue direction.The diffusion of image energy functional is controlled by the eigenvalue of im-age local Hessian along the direction.It overcomes the local limit of gradient pointing image feature and drives image energy functional to diffuse along corrected direction.Thus the blur of image feature is avoids.Numerical experiments on real ima-ges show that images interpolated by the proposed method have better interpolated edges and are almost artifact-free.