Research On Active Digital Image Forensics

In recent years,along with the rapid development of Internet technology and computer technology,people have become very convenient access to information and information,for example,we can through the mobile phone software all the time to get the latest hot news,weather forecast and traffic information.In this information,people seem to prefer to focus on the image information,because the visual impact causes people to get more realistic.People occasionally to see or hear,and the resulting from the confusion of how to identify true bogus,for example: a picture is true record the situation? Being tampered with,intentionally or unintentionally? Whether it is stealing?In fact,digital media is more easy to obtain,copied and tampered with,so as to get some interest,thus violated the legitimate rights and interests of copyright owners,even damage the reputation of others,hindered the normal development of related industries.In modern times,therefore,be badly in need of some kind of technology for digital media information provide a copyright protection and copyright identification and use of sound environment.Digital image forensics is such a responsibility: it can be carried out on the digital image analysis,identification and detection,to determine whether the transmission of images by tampering and forgery,determine the authenticity and reliability of image information.The research object of this paper is a digital images,our method for digital images using active approval to obtain evidence,to select a specific digital information for the approval of the image,and the corresponding transform in frequency domain.Using fast discrete cosine algorithm will be the original image and watermark information is processed to get a set of data,embedding watermark in intermediate frequency information,is obtained by inverse cosine transform its use and we want to embed information.Comparing with the original image is accordingly,we can extract the watermark information,after compare with the original watermark information,finallysummarizes the conclusions.Through information than can determine whether the image of the original image,such as display watermark information,suggests that has not been tampered with,increase its credibility.This study used the method for digital image forensics actively,one of the mainstream method of digital watermarking algorithm,frequency in DCT domain to embed invisible watermark original image within the implement anti-fake function,such as the carrier of the embedded watermark image is extracted watermark detection watermark and validation.Experiments show that: the digital watermark images are embedded on brightness,contrast and clipping attackers,extract the still more visible digital watermarking,does not affect the normal digital watermark image extraction and recognition;To the noise of different intensity of attack,although the extracted watermark with more noise,the watermark information is not obvious,but it can be to identify;But for rotation attack,although this algorithm can extract the watermark,also can see the outline of a general.Therefore,based on fast discrete cosine transform algorithm of active verification technology of digital image to hide information and anti-attack ability has good effect.