A structure-adaptive and structure-preserving image local warping method

Abstract

The invention discloses a structure self-adaptive and structure keeping image local distortion method. The method comprises the steps that under the condition of a single scale, the local edge direction and the local consistency of an image are analyzed firstly, a direction smoothing kernel function is designed accordingly, direction smoothing is conducted on an edge component of an initial biased field through the direction smoothing kernel function, and finally the image is distorted through the smoothed biased field. In order to keep a large-scale structure and a small-scale structure at the same time, a multi-scale image pyramid and a biased field pyramid are constructed, the biased fields are smoothed from top to bottom, iteration smoothing is conducted on the biased fields on each layer so that the smoothing effect can be improved, and each smoothed biased field on the former layer is used as the initial biased field of the biased fields on the next layer. According to the structure self-adaptive and structure keeping image local distortion method, the perception remarkable structural information in the image is analyzed and utilized, so that the effect that the image can be distorted without changing the type of important structures is achieved, the subjective perceived quality of the distorted image is improved, and the attack effect of the distorted image on a watermark system and the like is not influenced.

Description

technical field [0001] The invention relates to a method for locally distorting an image or a video frame and causing it to produce imperceptible geometric deformation, which is a structure-adaptive and structure-preserving image local distortion method, which is applicable to the fields of digital watermark system testing, digital image tampering and evidence collection system testing, etc. . Background technique [0002] Due to the rapid development of multimedia signal processing technology and the convenience of using commercial image processing software such as photoshop, the infringement of digital works such as images, videos and audios has become easier and easier to tamper with, resulting in a series of copyright Dispute issue. Digital watermark technology is an effective means to protect the copyright of digital works. It embeds secret information such as watermark into the digital carrier signal to be protected by embedding algorithm. When a copyright dispute oc...

AI Technical Summary

Problems solved by technology

However, neither of these two categories of methods takes into account the structure of the attacked image

Therefore, when applied to images with regular structures such as artificial scenes, it will cause perceptually obvious distortions. For example, for pixels located on the same edge, if the displacement along the direction of the vertical edge is inconsistent, the original straight edge can become curved, causing perceptual distortion and even discomfort, which severely limits its attack effectiveness

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