contour

An image as a stochastic signal is one of the most common forms of information. Protecting images from unauthorized access and applying is a correspondingly urgent task. This causes the use of well-known classical encryption methods in the case of image encryption. But the image is a signal that possesses, in addition to typical informativeness, also visual informativeness. Informativeness for modern image processing methods makes it possible to ensure unauthorized access.

Regarding image encryption, a crucial task is to implement the application of such an RSA algorithm which will provide an opportunity:

– not to decay the cryptographic stability of the RSA algorithm;

– to ensure complete noisiness of an image to prevent the application of methods of visual image processing.

The algorithm encryption-decryption recurrent images with clearly visible outlines binary linear forms and using elements of the RSA algorithm as the most resistant to unauthorized access to signals.

An application of the kvaternarn fractional-linear form with using the standard elements of the RSA algorithm for encryption and decryption of two-dimensional images is resistant to unauthorized access to images clearly distinguished contours.

The analysis of the histological and cytological images characteristics and automated biomedical images processing systems is provided. The structure of "contour-contour" transformation error and it evaluation is explored. A computer experiments of contours transformation error evaluation is done based on cytological images example.