An Isophote-Oriented Image Interpolation Method

This paper presents an isophote-oriented image interpolation method that attempts to produce smooth reconstructions of the image¿s level curves while still maintaining image fidelity. The proposed method employs an interpolation kernel that is obtained by looking for the explicit solution of a nonlinear PDE (partial differential equation). The PDE preserve the local continuation of isophotes (curves of constant intensity). By doing so, the curvature of the interpolated isophotes is reduced, and, thus, zigzagging artifacts are largely suppressed. Moreover, the interpolation techniques can preserve edge sharpness. In addition, the proposed methods can be used irrespective of the magnification factor (MF) and easily implemented due to their simple structure. Experiments show that images interpolated using the proposed method are both visually and quantitatively improved.