Region-based super-resolution for compression

Every user of multimedia technology expects good image and video visual quality independently of the particular characteristics of the receiver or the communication networks employed. Unfortunately, due to factors like processing power limitations and channel capabilities, images or video sequences are often downsampled and/or transmitted or stored at low bitrates, resulting in a degradation of their final visual quality. In this paper, we propose a region-based framework for intentionally introducing downsampling of the high resolution (HR) image sequences before compression and then utilizing super resolution (SR) techniques for generating anHR video sequence at the decoder. Segmentation is performed at the encoder on groups of images to classify their blocks into three different types according to their motion and texture. The obtained segmentation is used to define the downsampling process at the encoder and it is encoded and provided to the decoder as side information in order to guide the SR process. All the components of the proposed framework are analyzed in detail. A particular implementation of it is described and tested experimentally. The experimental results validate the usefulness of the proposed method. D. Barreto (B) · G. M. Callicó Research Institute for Applied Microelectronics, IUMA, University of Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Spain e-mail: [email protected] L. D. Alvarez · R. Molina Departamento de Ciencias de la Computación e I.A, Universidad de Granada, 18071 Granada, Spain e-mail: [email protected] A. K. Katsaggelos Department of Electrical Engineering and Computer Science, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3118, USA e-mail: [email protected] Multidim Syst Sign Process