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oai:www.ideals.illinois.edu:2142/80730 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Ahuja, Narendra Dugad, Rakesh Champalal 2015-09-25T20:07:52Z 2015-09-25T20:07:52Z 10000-01-01 2001 2001 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. Made available in DSpace on 2015-09-25T20:07:52Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3023046.pdf: 11168138 bytes, checksum: d97d40a110ec3bc306d51a0bfff6a399 (MD5) Previous issue date: 2001 Embargo set by: Seth Robbins for item 82012 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 242 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2001. http://hdl.handle.net/2142/80730 (MiAaPQ)AAI3023046 eng Engineering, Electronics and Electrical Fast Schemes for Video Denoising and Compressed Domain Image Size Change text Electrical Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.