Yuriy Rytsar

Metadata Representation for Semantic-Based Multimedia Security and Management

In this paper a novel approach to metadata representation for semantic-based multimedia security and management is proposed. This approach is based on semantically meaningful object segmentation and digital data hiding to facilitate image indexing as well as identification for dedicated image databases. An image is considered as a collection of the regions that correspond to objects, where these objects are associated with some hidden metadata describing some of their features. The metadata is hidden inside the raw images themselves for security and “portability” reasons. The embedding of hidden metadata allows moving an image from one database to another, as well as the insertion/cropping of objects from one image to another, while still preserving the associated descriptions. The perceptual invisibility of the integrated metadata confirms the high performance of this proposed object-based hidden metadata representation.

Tangible interactive system for document browsing and visualisation of multimedia data

In this paper we introduce and develop a framework for document interactive navigation in multimodal databases. First, we analyze the main open issues of existing multimodal interfaces and then discuss two applications that include interaction with documents in several human environments, i.e., the so-called smart rooms. Second, we propose a system set-up dedicated to the efficient navigation in the printed documents. This set-up is based on the fusion of data from several modalities that include images and text. Both modalities can be used as cover data for hidden indexes using data-hiding technologies as well as source data for robust visual hashing. The particularities of the proposed robust visual hashing are described in the paper. Finally, we address two practical applications of smart rooms for tourism and education and demonstrate the advantages of the proposed solution.

A new low-resolution and robust digital watermarking technique for the personalization of travel documents

This paper presents a new approach for the protection of travel documents. We propose a digital watermarking technique which requires for the verification process a low scanning resolution of at least 72 DPI. The approach is based on the wavelet decomposition and supports three key aspects: Message encoding is accomplished by iterative error correction codes satisfying a nearly optimal channel capacity. This encoding is based on specific modulation that requires for the implementation a significant lower complexity as the often applied M-array modulation. The watermark embedding is applied in the wavelet domain based on stochastic driven perceptional criteria for a good quality and invisibility. The watermarking process is considered as a communication process with side information. The approach utilizes two different watermarks, one for the channel state information estimation and one for the informative watermark which carries as a payload the hidden information.

Fast algorithm for impulsive noise suppression in highly corrupted aerophotographic images

A new fast effective approach for impulsive noise suppression in digitized aerophotographic images is presented in this paper. The filtering scheme consists of the global histogram analysis part to detect impulse corrupted pixels and the part of local adaptive interpolation of the intensity function of identified pixels by spatial modified order statistic value computed around these pixels. The proposed technique is characterized by its simplicity and better performing of the impulsive noise suppression while preserving fine details and edges of the image, especially where there is a high probability of the impulse occurrence. The advantages of developed approach in comparison with known adaptive identification filters are demonstrated by simulation results.