基于拉普拉斯金字塔的图像内容认证方法

Image Content Authentication Technique Based on Laplacian Pyramid

为了验证图像内容的真实性,提出了一种基于拉普拉斯金字塔的图像内容认证方法.在发送端首先对图像进行拉普拉斯金字塔分解,然后根据拉普拉斯金字塔分析原图像的光滑特性和细节特性,并对其特性进行编码得到特征值,最后将特征值加密后生成签名以水印方式嵌入原图像.在接收端将待测图像的特征值与从中抽取出的水印进行比较,对二者的差异图像以形态滤波的方法自动判断是否有图像内容被篡改,同时给出篡改的位置信息.实验结果表明,文中提出的图像内容验证算法可有效地检测出恶意篡改及其发生的位置,并可容忍由压缩、滤波、噪声污染等造成的失真.

This paper proposes a technique of image the authenticity of image content. First, the image is content authentication based on the Laplacian pyramid to verify decomposed into Laplacian pyramid before the transformation. Next, the smooth and detailed properties of the original image are analyzed according to the Laplacian pyramid, and the properties are classified and encoded to get the corresponding characteristic values. Then, the signature derived from the encrypted characteristic values is embedded in the original image as a watermark. After the reception, the characteristic values of the received image are compared with the watermark drawn out from the image, and the algorithm automatically identifies whether the content is tampered by means of morphologic filtration. The information of tampered location is presented at the same time. Experimental results show that the proposed authentication algorithm can effectively detect the event and location when the original image content is tampered, and can tolerate some distortions produced by compression, filtration and noise degradation .