Subpixel‐based image downsampling algorithm using content‐adaptive two‐dimensional FIR filters. Issue 8 (1st August 2014)

• Record Type: Journal Article
• Authors: Nam, Yeon‐Oh; Song, Byung Cheol
• Is Part Of: IET image processing. Volume 8:Issue 8(2014)
• Page Start: 445
• Page End: 454
• Publication Date: 2014-08-01
• Subjects: FIR filters -- image sampling -- inference mechanisms -- learning (artificial intelligence); subpixel‐based image downsampling algorithm -- content‐adaptive two‐dimensional FIR filters -- learning stage -- inference stage -- low‐resolution patch pairs -- high‐resolution patch pairs -- patch‐adaptive 2D FIR filters; Image processing -- Periodicals; 621.36705
• DOI: 10.1049/iet-ipr.2013.0325
• Languages: English
• ISSNs: 1751-9659

Abstract

Abstract : This study proposes a subpixel‐based image downsampling algorithm using content‐adaptive two‐dimensional (2D) finite impulse response (FIR) filters. The proposed algorithm consists of a learning stage and an inference stage. In the learning stage, using a sufficient number of low‐resolution (LR) and high‐resolution (HR) patch pairs, the authors compute optimal 2D FIR filters to synthesise LR patches of the highest quality from a specific HR patch and store the patch‐adaptive 2D FIR filters in a dictionary. In the inference stage, they explore candidates that best match to each HR input patch in the dictionary and synthesise LR patches by using their corresponding 2D FIR filters on a subpixel basis. The experimental results show that the proposed algorithm produces higher‐quality LR images on a patch basis than existing methods and entails no blur and aliasing artefacts.