CN111524056A

CN111524056A - Image blind watermarking method for rapidly analyzing image source and protecting image copyright

Info

Publication number: CN111524056A
Application number: CN201910102517.4A
Authority: CN
Inventors: 郭英
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-02-01
Filing date: 2019-02-01
Publication date: 2020-08-11

Abstract

The invention relates to an image blind watermarking method for rapidly analyzing an image source and protecting the image copyright, belonging to the technical fields of digital image processing, computer application, computer safety and the like. Firstly, carrying out matrix chaotic encryption on an image, then carrying out wavelet transformation on the image, decomposing the transformed image into an LL1 sub-band, an HL1 sub-band, an LH1 sub-band and an HH1 sub-band, decomposing the LH1 sub-band, then carrying out Fourier transformation, adding a watermark of a two-dimensional code with a hyperlink address and an image copyright page address into the transformed image, then carrying out wavelet reconstruction, and then carrying out chaotic matrix decryption on the reconstructed image. The watermark information is extracted according to the operation mode of watermarking. The method can well embed the watermark without damaging the original image, blind extraction of the watermark is completed without the need of the original image for watermark extraction, and the method is applied to image hyperlink and image copyright information protection and has certain practical value.

Description

Image blind watermarking method for rapidly analyzing image source and protecting image copyright

Technical Field

The invention belongs to the technical field of digital image processing, computer application, computer security and the like.

Background

At present, the source of the image obtained by the computer is often the image source obtained by the hyperlink address of the image, but as long as the image is downloaded locally, the hyperlink of the image will fail, and meanwhile, the image source cannot be tracked, and the image works published by the original author cannot be effectively protected.

The protection of the image author right is always one direction of computer science exploration, and at present, a computer adopts an image watermarking method to protect the ownership of an author, but the traditional method is based on a spatial domain implementation, and some identification symbols are added on an image, so that the original image is damaged, the image cannot resist attack, and the image is easy to modify. At present, a time-frequency method is generally used for processing watermarks, but the embedded watermarks which do not damage original images, have certain robustness and can resist attacks are achieved, and the operation is often complex.

The invention mainly applies AES website encryption, two-dimension code technology, random number chaos processing, fast Fourier transform and wavelet technology.

Advanced Encryption Standard (AES), also known as Rijndael Encryption, is a block Encryption Standard adopted by the federal government in the united states. This standard, which is used to replace the original DES, has been analyzed by many parties and is widely used throughout the world. Through the five-year selection process, the advanced encryption standard was released by the National Institute of Standards and Technology (NIST) in FIPS PUB 197 at 11/26/2001 and became an effective standard at 26/5/2002. In 2006, the advanced encryption standard has become one of the most popular algorithms in symmetric key encryption. The method for encrypting the website can use uniform key management, the instant image connection address is modified, and the hidden content of the two-dimensional code cannot be successfully analyzed without the key.

The two-dimensional Code is also called as a two-dimensional Bar Code, a common two-dimensional Code is a QR Code, and QR is known as Quick Response, which is an ultra-popular coding mode on mobile equipment in recent years, and compared with the traditional Bar Code, the two-dimensional Code can store more information, can also represent more data types, and can properly tolerate faults.

The random number chaos processing means that under the condition that the seed number is not changed, two groups of random integers are generated, and the pixel sequence of the image is disturbed by the two groups of random seed numbers, which is equivalent to that the original image is encrypted, namely the copyright of the image is protected.

As is well known, the fourier transform of an image is the decomposition of the image signal into various sine waves of different frequencies. Likewise, a wavelet transform is the decomposition of an image signal into a set of wavelets shifted and scaled from the original wavelets. The wavelet is called an image microscope in image processing because its multi-resolution decomposition capability can decompose and strip picture information layer by layer. The means of stripping is by low-pass and high-pass filters,

two-dimensional image signal decomposition

For two-dimensional image signals, two-dimensional wavelet multi-resolution decomposition can be realized by filtering in the horizontal and vertical directions respectively. And dividing the decomposed sub-images through two-dimensional discrete wavelet transform. Wherein:

(l) The LL subband is the wavelet coefficient resulting from convolution with a low-pass wavelet filter from two directions, which is an approximate representation of the image. (2) The HL subband is a wavelet coefficient generated by convolving the image in the row direction with a low-pass wavelet filter and then convolving the image in the column direction with a high-pass wavelet filter, and represents the horizontal direction singular characteristics of the image. (horizontal sub-band)

(3) The LH subband is a wavelet coefficient generated by convolving with a high-pass wavelet filter in the row direction and then convolving with a low-pass wavelet filter in the column direction, and represents a vertical direction singular characteristic of an image. (vertical sub-band)

(4) The HH subband is a wavelet coefficient generated by convolution of two directions with a high-pass wavelet filter, which represents a diagonal edge characteristic of an image. (diagonal belts)

(the first letter indicates the processing in the column direction, the second letter indicates the processing in the row direction, and the singular character of the image is retained by the low pass and filtered by the high pass)

Reconstruction of two-dimensional images

And performing inverse transformation according to the method to restore the image.

The digital watermarks are classified into blind watermarks and non-blind watermarks according to whether the process of mercury extraction needs an original image. The blind watermark does not require the participation of the original image in the extraction process, and the non-blind watermark does require the participation of the original image in the detection process.

Disclosure of Invention

Fast Fourier Transform (FFT), a general term for an efficient and fast computational method for computing a Discrete Fourier Transform (DFT) using a computer, is abbreviated as FFT. The fast fourier transform was proposed in 1965 by j.w. kuri and t.w. graph base. The multiplication times required by a computer for calculating the discrete Fourier transform can be greatly reduced by adopting the algorithm, and particularly, the more the number N of the transformed sampling points is, the more remarkable the calculation amount of the FFT algorithm is saved.

The invention relates to an image blind watermarking method for rapidly analyzing an image source and protecting the image copyright, belonging to the technical fields of digital image processing, computer application, computer safety and the like. Referring to a flow chart of fig. 1, firstly performing matrix chaotic encryption on an image, then performing wavelet transformation on the image, decomposing the transformed image into an LL1 sub-band, an HL1 sub-band, an LH1 sub-band and an HH1 sub-band, decomposing the LH1 sub-band, then performing Fourier transformation, adding a watermark of a two-dimensional code with a hyperlink address and an image copyright page address to the transformed image, then performing wavelet reconstruction, and performing chaotic matrix decryption on the reconstructed image. The watermark information is extracted according to the operation mode of watermarking. The method can well embed the watermark without destroying the original image. The watermark extraction does not need the original image, namely the blind extraction of the watermark is finished, and the method is applied to image hyperlink and image copyright information protection and has certain practical value.

Claims

1. The method is characterized in that a two-dimensional code technology for generating the encrypted information is adopted to ensure the robustness and the safety of the watermark.

2. The method of claim 1, wherein wavelet decomposition, random matrix, AES algorithm encryption chaining address and two-dimensional code techniques are used in combination to process and extract information.

3. The method of claim 1, wherein the image link address can be extracted quickly to replace the hyperlink of the original image.

The method of claim 1, wherein copyright protection can be performed on the image to ensure security of the digital watermark.