每年出版 12 期
ISSN 打印: 0040-2508
ISSN 在线: 1943-6009
Indexed in
Mathematical Model of a Digital Image in the JPEG Format
摘要
A mathematical model of an image in the JPEG format is analyzed. The proposed model describes a discrete cosine transform (DCT), takes into account local features of the image, module noise, boundary nonhomogeneity and their interrelation with the file quality. Besides, the statistical parameters of the distribution of DCT coefficients, i.e., mathematical expectation, dispersion, and covariance function, have been determined. In analyzing images, the model allows evaluation of statistical characteristics in the space and frequency regions. An increase of the attributes space is required for improving the accuracy of the result of detection of steganographic embedding in natural images. The model can be used for developing algorithms for classification of images in databases and systems of security and protection against unauthorized modification of the design products.