A Method of Information Hiding in Sonar Image Combining Fractal and Wavelet

Abstract

The invention provides a sonar image information hiding method with a fractal and a wavelet combined. The method comprises the steps of (1) enabling a 3-bit binary system sequence to serve as a unit, converting information to decimal system sequences with values of 0 to 7; (2) enabling a sonar image to serve as a carrier, conducting wavelet transformation for the carrier image, dividing father-blocks and sub-blocks in different sub-band images which are arranged in the same direction of a wavelet tree; (3) using the decimal system sequences with the values of 0 to 7 to serve as classes of parameter appointed father-block affine transformation, calculating the optimal contrast ratio and luminance of the transformation blocks, replacing corresponding sub-blocks, writing down the position of the replaced sub-block; (4) sequentially processing each father-block, if the target sub-block is replaced, repeating the step of (3); (5) finishing embedding all the information, conducting wavelet inverse transformation for the carrier image, and obtaining a hiding image. According to the fact that the information is embedded through control of classes of affine transformation, an original image block with 1 bit information embedded can improvingly provided with 3 bit information in an embedded mode, and a volume for information hiding is improved.

Description

Technical field [0001] The invention relates to a method for hiding sonar image information. Background technique [0002] At present, due to the development of information hiding technology, there are more and more types of information hiding algorithms, and they are changing from simple spatial algorithms to frequency domain algorithms. Among them, DCT new information hiding algorithms, wavelet domain information hiding algorithms and other methods have been widely used the study. After research, it is found that the combined algorithm of wavelet and fractal has a good development prospect. The basis of fractal application is that the target image and the source image of the radiological transformation are required to have greater similarity, and the image obtained by the wavelet transformation in the same direction Images between different layers have great similarities, so it is very suitable to combine the two algorithms for information hiding. However, because the wavelet...

AI Technical Summary

Problems solved by technology

However, because the wavelet embedding algorithm belongs to the frequency domain algorithm, the embedding capacity is limited, and the application in covert communication is also greatly restricted.

In addition, since the research of image information hiding technology is concentrated in optical images, the application of image information hiding in sonar images has not yet been researched and experimented.

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