扩散修复是一种常见的小面积图像篡改手段,考虑到扩散修复引入的模糊效应,提出了一种梯度域导向滤波增强的图像扩散修复取证算法。因伪造图像在未修复区域结构纹理清晰,而模糊效应会导致修复区域纹理发生一定的改变,所以梯度域导向滤波能够保留未修复区域的纹理结构,从而突显修复区域的模糊效应。鉴于篡改信息在不同颜色通道里均有不同程度的体现,对输入图像的各个颜色通道分别进行梯度域导向滤波增强,从多角度捕捉图像修复带来的影响。实验结果表明,该方法不仅可以有效检测和定位扩散修复区域,且比现有的方法检测性能更好。

Diffusion-based inpainting is a common method of small-area image tampering, considering the blurring effect introduced by diffusion-based image inpainting, this paper proposes a method of diffusion-based image inpainting forensics via gradient domain guided filtering enhancement. Since the texture of the forged image is clear in the untouched regions, and the blurring effect results in some texture changes in the inpainted regions, gradient domain guided filtering can better preserve the texture structure of the untouched regions and highlight the blurring effect of the inpainted regions. In view of the fact that the tampered information is reflected to different extend in different color channels, the gradient domain guided filtering is applied to enhance each color channel of the input image, which captures the impact of image inpainting from multiple perspectives. Experimental results show that this method can not only detect and locate the diffusion-based image inpainting regions effectively, but also has better detection performance than the existing methods.