CWT-QIM digital blind watermarking algorithm for RAW format image

Abstract

The invention discloses a CWT-QIM digital blind watermarking algorithm, which includes the embedding process and the extracting process of watermark. The embedding process of watermark includes the generation of watermark image, selection of an embedded area, DCT transform and vector quantization modulation-based embedding; the watermark extraction process is basically the inverse operation of thewatermark embedding process; the algorithm of the invention has excellent robustness and transparency, can effectively resist JPEG image compression, Gaussian noise, median filter, salt and pepper noise, scaling, rotation, cropping and other image attacks, improve the performance of digital watermarking algorithm, quantization and embedding watermark information, and can be extracted blindly without the original carrier image, can be easily and effectively applied to digital content authentication or digital copyright protection and other fields.

Description

technical field [0001] The invention relates to a CWT-QIM digital blind watermark algorithm for RAW format images, belonging to the technical field of image processing. Background technique [0002] At present, thanks to the continuous development of digital cameras and network technologies, the storage, processing, dissemination and use of high-resolution digital images and videos are becoming more and more frequent, and the image copyright issues involved are also emerging in endlessly; traditional digital watermarks are based on the embedded position. Different watermarking algorithms can be divided into spatial domain and variable domain. The former refers to embedding watermark directly in the spatial domain of the original information, while the latter is to embed the watermark in the transform domain. However, traditional digital watermarking has one or more of the following defects to varying degrees : First, the embedding of the watermark is embedded in the hardware...

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Problems solved by technology

[0002] At present, thanks to the continuous development of digital cameras and network technologies, the storage, processing, dissemination and use of high-resolution digital images and videos are becoming more and more frequent, and the image copyright issues involved are also emerging in endlessly; traditional digital watermarks are based on the embedded position. Different watermarking algorithms can be divided into spatial domain and variable domain. The former refers to embedding watermark directly in the spatial domain of the original information, while the latter is to embed the watermark in the transform domain. However, traditional digital watermarking has one or more of the following defects to varying degrees : First, the embedding of the watermark is embedded in the hardware, and the robustness is not strong enough, especially with the upgrade of the camera equipment, the image size increases from 720p to 2k or even 4k, and the robustness of such high-definition image scaling is not considered Second, as the network is developing day by day, users need to embed additional watermarks for images in RAW format that have been captured or processed. However, the current research is only to embed watermarks in the process of CFA, and what is obtained is JPEG images with embedded watermarks. The watermark is not embedded in the RAW image; the third is that in the absence of the original image, when the watermark image is attacked such as resolution change operation, it is usually impossible to detect and extract the watermark information, and there is no ability to detect and extract similar attacks. Robustness of

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