Foveated image watermarking

The spatial resolution of the human visual system (HVS) decreases rapidly away from the point of fixation (foveation point). By exploiting this fact, we propose a watermarking approach that embeds the watermark energy into the image peripheral according to foveation-based HVS contrast thresholds. Compared to the other HVS-based watermarking methods, the simulation results demonstrate an improvement in the robustness of the proposed approach against image degradations, such as JPEG compression, cropping and additive Gaussian noise, in terms of subjective measures, based on foveation. In addition, the method proposed for still images is adapted for video and the robustness of the adapted method is tested against ITU H.263+ coding.


Simultaneous bottom-up/top-down processing in early and mid level vision
Erdem, Mehmet Erkut; Tarı, Zehra Sibel; Department of Computer Engineering (2008)
The prevalent view in computer vision since Marr is that visual perception is a data-driven bottom-up process. In this view, image data is processed in a feed-forward fashion where a sequence of independent visual modules transforms simple low-level cues into more complex abstract perceptual units. Over the years, a variety of techniques has been developed using this paradigm. Yet an important realization is that low-level visual cues are generally so ambiguous that they could make purely bottom-up methods ...
Relative consistency of projective reconstructions obtained from the same image pair
Otlu, Burcak; Atalay, Mustafa Ümit; Hassanpour, Reza (World Scientific Pub Co Pte Lt, 2006-08-01)
This study obtains projective reconstructions of an object or a scene from its image pair and measures relative consistency of these projective reconstructions. 3D points are estimated from an image pair using projective and epipolar geometry. Two measures are presented for verification of projective reconstructions with each other. These measures are based on the equality of ratios between the x-, y- and z-coordinates of 3D reconstructed points which are obtained from the same corresponding points. This in...
Temporal watermarking of digital video
Koz, A; Alatan, Abdullah Aydın (2003-04-11)
A video watermarking method is presented, based on the temporal sensitivity of Human Visual System (HVS). The method exploits the temporal contrast thresholds of HVS to determine the spatio-temporal locations, where the watermark should be embedded, and the maximum strength of watermark, which still gives imperceptible distortion after watermark insertion. The robustness results indicate that the proposed scheme survives video distortions, such as additive Gaussian noise, ITU H.263+ coding at medium bit rat...
Semantic data modeling of spatiotemporal database applications
Yazıcı, Adnan; Sun, N (Wiley, 2001-07-01)
Due to the ubiquity of space-related and time-related information, the ability of a database system to deal with both spatial and temporal phenomenon facts in a spatiotemporal applications is highly desired. However, uncertain and fuzzy information in these applications highly increases the complexity of database modeling. In this paper we introduce a semantic data modeling approach for spatiotemporal database applications. We specifically focus on various aspects of spatial and temporal database issues and...
Improving interactive classification of satellite image content
Tekkaya, Gökhan; Atalay, Mehmet Volkan; Department of Computer Engineering (2007)
Interactive classication is an attractive alternative and complementary for automatic classication of satellite image content, since the subject is visual and there are not yet powerful computational features corresponding to the sought visual features. In this study, we improve our previous attempt by building a more stable software system with better capabilities for interactive classication of the content of satellite images. The system allows user to indicate a few number of image regions that contain a...
Citation Formats
A. Koz and A. A. Alatan, “Foveated image watermarking,” 2002, Accessed: 00, 2020. [Online]. Available: