A Study on Fast Method for Image Up-Sampling Using Neighboring Blocks in DCT Domain
Tomio Goto, Yoshihiro Shinkai, Masaru Sakurai, Tadashi Kitamura · The Journal of The Institute of Image Information and Television Engineers · 2007
We have studied a number of approaches to processing resolution conversion in the discrete cosinetransform (DCT) domain because the JPEG, MPEG-1, -2, -4 standards based on DCT are widely used for image/video compression. Resolution conversion in the DCT domain is generally processed using a DCT block, which can lead to blocky noise appearing in scaled-up images. We have developed a method of high speed processing so that the time taken to scale up images is reduced. We developed the method because a method we previously developed to improve image quality during resolution conversion in the discrete cosine transform (DCT) domain was too slow at scaling up images. This previous method takes in uses the correlation between DCT blocks. It produces fine images without blocky noise and improves PSNR and GBIM.