In this paper we propose an automatic technology for extraction of latent images from printed media such as documents, banknotes, financial securities, etc. This technology includes image processing by adaptively constructed Gabor filter bank for obtaining feature images, as well as subsequent stages of feature selection, grouping and multicomponent segmentation. The main advantage of the proposed technique is versatility: it allows to extract latent images made by different texture variations. Experimental results showing performance of the method over another known system for latent image extraction are given.
This paper presents a new method for high-capacity information hiding in digital video and algorithms of embedding and extraction of hidden information based on this method. These algorithms do not require temporal synchronization to provide robustness against both malicious and non-malicious frame dropping (temporal desynchronization). At the same time, due to randomized distribution of hidden information bits across the video frames, the proposed method allows to increase the hiding capacity proportionally to the number of frames used for information embedding. The proposed method is also robust against “watermark estimation” attack aimed at estimation of hidden information without knowing the embedding key or non-watermarked video. Presented experimental results demonstrate declared features of this method.
This paper describes a study to find the best error diffusion kernel for digital halftoning under various restrictions on the number of non-zero kernel coefficients and their set of values. As an objective measure of quality, WSNR was used. The problem of multidimensional optimization was solved numerically using several well-known algorithms: Nelder– Mead, BFGS, and others. The study found a kernel function that provides a quality gain of about 5% in comparison with the best of the commonly used kernel introduced by Floyd and Steinberg. Other kernels obtained allow to significantly reduce the computational complexity of the halftoning process without reducing its quality.