High-volume reversible watermarking method based on remainder invariance

Abstract

The invention discloses a high-volume reversible watermarking method based on remainder invariance. The method comprises a watermark embedding process and a watermark extraction and original image recovery process. A integer transformation provided by the invention removes additive terms and reduces embedding distortion; the integer transformation is composed of only a prediction process, and involves predicting each pixel in a block by using the mean value of the block, enabling each prediction error before a final prediction error in a sub-block to carry watermarking information and enabling a final pixel to be only predicted but carry no watermarking information so as to ensure the reversibility of the integer transformation; and by using the characteristic that the remainder obtained through the mean value of an image sub-block being divided by a given embedding parameter remains untransformed beforehand and afterwards, the integer transformation can help to recover original pixels and watermarking information without distortion. Therefore, by the provided method, improvements to a great extent are made in terms of both embedding capacity and recovery image quality.

Description

technical field [0001] The invention relates to the technical field of multimedia signal processing, in particular to a high-capacity reversible watermarking method based on remainder invariance. Background technique [0002] Traditional digital watermarking technology will cause permanent distortion of the host image. However, in some practical applications, a little bit of permanent modification of the host image is not allowed, such as medical, military and judicial fields. Taking medical images as an example, distortion of any kind is not allowed. The acquisition of any medical image requires the support of precision instruments and expensive medical expenses. More importantly, distortion may cause potential misdiagnosis. For example, for an ECG (electrocardiographic) signal graph, any abnormality in the signal curve may be interpreted as a certain pathological feature. Therefore, traditional digital watermarking techniques are not suitable for medical images. A tech...

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Problems solved by technology

Therefore, due to the introduction of this additional item, Alatter introduces an additional embedding distortion of up to 2 per pixel, which will directly lead to a serious decrease in the visual quality of the image

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