Universitat Autònoma de Barcelona
Region-of-Interest (ROI) in an image or video signal contains important information and may be used for access control at various qualities using multiresolution analysis (MRA). This paper proposes a novel quality access control method of compressed color image by modulating the coefficients of ROI at various levels. Data modulation causes visual degradation in the original image and plays the key role in access control through reversible process. The modulation information, in the form of a secret key, is embedded in non-ROI part of the chrominance blue (Cb) channel of the color image using quantization index modulation (QIM). Lifting based DWT, rather than conventional DWT, is used to decompose the original image in order to achieve two-fold advantages, namely (1) better flexibility and low loss in image quality due to QIM and (2) better decoding reliability that leads to better access control. Only the authorized users having the full knowledge of the secret key restore the full quality of ROI. Simulation results duly support this claims.
English
Control d'accés; Domini comprimit; Retorn de la inversió; Wavelet; Elevació; Marca d'aigua; Control de acceso; Dominio comprimido; Retorno de la inversión; Elevación; Marca de agua; Access Control; Compressed Domain; ROI; Lifting; Watermarking; QIM
ELCVIA. Electronic letters on computer vision and image analysis ; V. 8 n. 2 (2009) p. 51-67
open access
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