A Ringing-Artifact Reduction Method for Block-DCT-Based Image Resizing

This paper proposes a new ringing-artifact reduction method for image resizing in a block discrete cosine transform (DCT) domain. The proposed method reduces ringing artifacts without further blurring, whereas previous approaches must find a compromise between blurring and ringing artifacts. The proposed method consists of DCT-domain filtering and image-domain post-processing, which reduces ripples on smooth regions as well as overshoot near strong edges. By generating a mask map of the overshoot regions, we combine a ripple-reduced image and an overshoot-reduced image according to the mask map in the image domain to obtain a ringing-artifact reduced image. The experimental results show that the proposed method is computationally faster and produces visually finer images than previous ringing-artifact reduction approaches.