J4 ›› 2016, Vol. 43 ›› Issue (1): 151-156.doi: 10.3969/j.issn.1001-2400.2016.01.027

• Original Articles • Previous Articles     Next Articles

Rational function for image interpolation based on human contrast sensitivity

LIU Yifang1,2;ZHANG Yunfeng1,2;GUO Qiang1,2;ZHANG Caiming1,2   

  1. (1. School of Computer Science and Technology, Shandong Univ. of Finance and Economics, Ji'nan  250014 China;
    2. Shandong Provincial Key Lab. of Digital Media Technology, Ji'nan  250014, China)
  • Received:2014-10-11 Online:2016-02-20 Published:2016-04-06
  • Contact: LIU Yifang E-mail:sdliuyifang@163.com

Abstract:

A new image interpolation algorithm based on the rational function model with both smoothing and surface constraints is proposed. The rational function has a simple and explicit expression with two parameters. The image edge regions can be detected adaptively by using contour analysis. Basically, the detective threshold is selected based on the rational function construction. Selecting different parameters in the rational function model, the edge regions and smooth regions are interpolated by bicubic interpolation and rational interpolation, respectively. The optimal rational interpolation parameters can be obtained with a set of exact solutions by solving a maximization problem based on the contrast sensitivity enhancement of human eyes. Experimental results demonstrate that the proposed method achieves competitive performance with the state-of-the-art interpolation algorithms, especially in image details features.

Key words: rational interpolation, image interpolation, human contrast sensitivity, contour analysis, adaptively optimize parameters