An angle QIM watermarking in STDM framework robust against amplitude scaling distortions

Abstract

Quantization index modulation (QIM) watermarking proposed by Chen and Wornell provides computational efficient blind watermarking based on Costa's dirty paper codes. The limitation of this is its vulnerability against amplitude scaling distortion. The present work is proposed to solve this problem based on angle QIM within spread transform dither modulation (STDM) framework. AQIM embeds the information by quantizing the angle formed by the host-signal vector with respect to the origin of a hyperspherical coordinate system as opposed to quantizing the amplitude of pixel values. It has been shown experimentally that the proposed work not only provides the resistance against this valumetric scaling distortion but also against non-linear, gamma correction and constant luminance change. © 2009 Springer Berlin Heidelberg.