基于块效应网格偏移的重获取JPEG图像篡改检测

重获取图像是原始或篡改后的图像经过中间媒介的映射后再次拍摄获取的图像，一张高质量的重获取伪造图像很难通过人眼判别真伪。针对JPEG格式的重获取图像篡改操作，提出了一种重压缩块效应网格偏移的检测方法。重获取图像由于再获取过程会引入与原图不相关的背景信息，该图像进行多次压缩会产生块效应网格偏移，即重压缩产生的块效应网格会与原始的网格错匹配，利用图像的平均信息损失量进行块效应网格是否发生偏移来检测图像的原始性。实验表明，该方法比已有的重获取图像检测方法准确率更高，且平均检测时间更短。

JPEG recapture image tamper detection method based on block effect grid offset

Recaptured images are captured original or distorted image shown on the intermediaries,a high-quality recapture image is difficult to distinguish the authenticity of the human eye.Aimed at the tampering operation of JPEG image,a method of detecting block effect grid offset due to re-compression was proposed.The original image was compressed multiple times did not produce the block effect of the grid offset,and the recapture image,because of the recapture process would introduce background information that was not related to the original image,the re-compression of the block effect grid with the original grid is mismatched,and the average information loss amount of the image was used to detect whether the block effect grid generates an offset or not to detect the recapture image.Experiments show that this method is more accurate than the existing recapture image detection method,and the average detection time is shorter.