AbstractsComputer Science

MULTIHYPOTHESIS PREDICTION FOR COMPRESSED SENSING AND SUPER-RESOLUTION OF IMAGES

by Chen Chen




Institution: Mississippi State University
Department: Electrical and Computer Engineering
Degree: MS
Year: 2012
Keywords: Compressed Sensing; Tikhonov Regularization; Multihypothesis Prediction; Image Super-resolution; Hyperspectral Data
Record ID: 1943526
Full text PDF: http://sun.library.msstate.edu/ETD-db/theses/available/etd-03212012-113557/


Abstract

A process for the use of multihypothesis prediction in the reconstruction of images is proposed for use in both compressed-sensing reconstruction as well as single-image super-resolution. Specifically, for compressed-sensing reconstruction of a single still image, multiple predictions for an image block are drawn from spatially surrounding blocks within an initial non-predicted reconstruction. The predictions are used to generate a residual in the domain of the compressed-sensing random projections. This residual being typically more compressible than the original signal leads to improved compressed-sensing reconstruction quality. To appropriately weight the hypothesis predictions, a Tikhonov regularization to an ill-posed least-squares optimization is proposed. An extension of this framework is applied to the compressed-sensing reconstruction of hyperspectral imagery is also studied. Finally, the multihypothesis paradigm is employed for single-image superresolution wherein each patch of a low-resolution image is represented as a linear combination of spatially surrounding hypothesis patches.