Image Up-Sampling Using Discrete Wavelet Transform

Image up-sampling is found to be a very effective technique useful in today’s digital image processing applications or rendering devices. In image upsampling, an image is enhanced from a lower resolution to a higher resolution with the degree of enhancement depending upon application requirements. It is known that the traditional interpolation based approaches for up-sampling, such as Bilinear or Bicubic interpolation, blur the resultant images [1, 2]. Furthermore; in color imagery, these interpolation based up-sampling methods may have color infringing artifacts in the areas where the images contain sharp edges and fine textures. In this paper, we present an interesting up-sampling algorithm using 9/7 bi-orthogonal Spline filters based Discrete Wavelet Transform (DWT). The proposed method preserves much of the sharp edge features in the image, and lessens the amount of color artifacts. Effectiveness of the proposed algorithm has been demonstrated based on evaluation of PSNR and * ab E ∆ quality metrics of the original image and the reconstructed image.