Использование многоканальных космических снимков для анализа годовой динамики вегетационной активности
The relevance. One of the areas of digital image processing, including images of Earth remote sensing, is associated with the embedding of additional information into such images for various purposes. Embedding of additional information into a digital image leads to distortion of the digital image natural model, as well as to the possible occurrence of visual artifacts. In the case of images of Earth remote sensing, such distortions may entail, for example, distortion of the object boundaries, as a result of which further analysis of the images will lead to incorrect results. Therefore, the studies aimed at finding new ways to reduce distortions caused by embedding additional information are relevant. The aim of the research is to improve the quality of steganographic embedding of information in the coefficients of discrete cosine transform of Earth remote sensing images by developing an improved embedding algorithm based on the QIM method and ensuring the correction of distortions of the natural image model in the frequency domain. Objects: algorithms for steganographic embedding of information in the coefficients of digital images discrete cosine transform. Methods: QIM steganographic method, methods of mathematical statistics, computational experiments. Results. The paper proposes a new approach to minimizing the distortion of the natural model of a digital image in the discrete cosine transform domain, based on changing the quantization step depending on the local image characteristics in the frequency domain. The result of the work is an improved algorithm for embedding the information in the coefficients of discrete cosine transform of images of Earth remote sensing, combining this approach with an approach to ensure the correct extraction of embedded information proposed by the authors earlier. The results of the experiments show that the developed algorithm, along with ensuring the accuracy of extraction, can significantly reduce the distortions introduced into frequency coefficients and ensure statistical indistinguishability of the cover images and stego images in 75 % of cases.
The article focuses on the methods of vegetation cover mapping on the water protection zones of the rivers in the Northern part of the Nenets Autonomous District (NAD), based on remote sensing, and field data. The details of the processing of multispectral satellite images of high and medium spatial resolution and panchromatic images for the tundra territories are shown. For the first time the detailed maps of plant cover for the water protection zones on the territory of the NAD rivers were composed on the basis of remote sensing data. Locations of the plant communities, subjected to human impact were detected either.
The collection includes abstracts of reports by specialists from organizations actively leading the development of new methods and systems for remote sensing of the Earth from space. The results are presented on methodological and hardware issues of remote sensing, on the development of methods for processing and interpretation of satellite remote sensing data of natural environments and the creation of satellite Earth monitoring systems.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.