计算机科学
計算機科學
계산궤과학
COMPUTER SCIENCE
2010年
2期
269-273
,共5页
图像取证%图像篡改%块效应%JPEG
圖像取證%圖像篡改%塊效應%JPEG
도상취증%도상찬개%괴효응%JPEG
Image forensics%Image forgery%Blocking artifacts%JPEG
不同JPEG栅格位置或不同压缩质量的图像区域被合成为篡改图像时会出现JPEG块效应的差异,据此提出了一种能自动定位篡改区域的图像盲被动取证方法.算法先通过一种基于小波的图像去噪方法提取噪声,利用噪声衡量局部JPEG块效应以提高块效应信号的信噪比;然后通过迭代方法寻找到合适的阈值,在块效应直方图中分离出篡改区域.针对不同类型的篡改区域的实验说明了算法的有效性.
不同JPEG柵格位置或不同壓縮質量的圖像區域被閤成為篡改圖像時會齣現JPEG塊效應的差異,據此提齣瞭一種能自動定位篡改區域的圖像盲被動取證方法.算法先通過一種基于小波的圖像去譟方法提取譟聲,利用譟聲衡量跼部JPEG塊效應以提高塊效應信號的信譟比;然後通過迭代方法尋找到閤適的閾值,在塊效應直方圖中分離齣篡改區域.針對不同類型的篡改區域的實驗說明瞭算法的有效性.
불동JPEG책격위치혹불동압축질량적도상구역피합성위찬개도상시회출현JPEG괴효응적차이,거차제출료일충능자동정위찬개구역적도상맹피동취증방법.산법선통과일충기우소파적도상거조방법제취조성,이용조성형량국부JPEG괴효응이제고괴효응신호적신조비;연후통과질대방법심조도합괄적역치,재괴효응직방도중분리출찬개구역.침대불동류형적찬개구역적실험설명료산법적유효성.
Inconsistency of blocking artifacts is introduced when image regions with different JPEG quality factors or grids are spliced for forgery.A novel image forgery detection method was proposed to automatically locate the tampered regions.The compression noise was firstly extracted from the images using a wavelet-based denoising filter.The proposed method measured the JPEG blocking artifact using the compression noise to improve the SNlL Then an appropriate threshold was found using an iterative method to separate tampered regions in the histogram of blockiness metrics.Experimental resuhs were presented to demonstrate the effectively and reliability of our method.
