Image interpolation using wavelet-based contour estimation

Successful image interpolation requires proper enhancement of high frequency content of image pixels around edges. In this paper, we introduce a simple edge model to estimate high resolution edge profiles from lower resolution values. Pixels around edges are viewed as samples taken from one dimensional (1-D) continuous edge profiles according to 1-D smooth edge contours defining the sampling instants. The image is highpass filtered by wavelets and subpixel edge lo-cations are estimated by minimizing the modeling error in the wavelet domain. Interpolation is carried out by apply-ing the model, wherever applicable, together with a base-line interpolator (here, bilinear) in order to make edges look sharper without introducing artifacts. The results are com-pared to bilinear interpolation, and significant improvement in terms of SNR, edge sharpness and contour smoothness is observed. 1