Fast Schemes for Video Denoising and Compressed Domain Image Size Change

A fast scheme is devised for obtaining a smaller or bigger version of an image when both the input and output images are in compressed format. This is accomplished by designing the down- and upsizing filters to take into account the specific symmetry and orthogonality properties of the transform used for compression. Specifically, the filter is designed so that the transform of the filter matrix is sparse rather than the filter matrix itself being sparse. This is important because the processing is to be carried out in the transform domain. The scheme is described for the case when the input and output images are in terms of 8 x 8 DCT (discrete cosine transform) coefficients, but is also applicable to other transforms such as the Fourier transform. Huge gains in perceptual quality and PSNR are obtained with much less computation. We also provide an analysis of the aliasing effects of our scheme. Further, we describe how this scheme can be applied to spatially scalable video compression.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Dugad, Rakesh Champalal

Contributors dc:contributor

• Ahuja, Narendra

• Engineering, Electronics and Electrical

Language dc:language

eng

Identifier

(MiAaPQ)AAI3023046

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/80730