Open AccessSubpixel‐based image downsampling algorithm using content‐adaptive two‐dimensional FIR filters
Author(s) -
Nam YeonOh,
Song Byung Cheol
Publication year - 2014
Publication title -
iet image processing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.401
H-Index - 45
eISSN - 1751-9667
pISSN - 1751-9659
DOI - 10.1049/iet-ipr.2013.0325
Subject(s) - upsampling , subpixel rendering , finite impulse response , computer science , algorithm , artificial intelligence , adaptive filter , matching pursuit , pattern recognition (psychology) , aliasing , decimation , computer vision , filter (signal processing) , mathematics , image (mathematics) , pixel , compressed sensing
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.