2Mosaic_0_2_2.zip_zip_隐藏

2Mosaic 0.2.2 for Microsoft Windows 95/98/NT -------------------------------------------- 2Mosaic is a 'presentation' attack against digital watermarking systems, which is of quite general applicability and which possesses the initially remarkable property that a marked image can be unmarked and yet still rendered in exactly the same way as the marked image by a standard browser. The attack was motivated by a fielded automatic system for copyright piracy detection, consisting of a watermarking scheme plus a web crawler that downloads pictures from the net and checks whether they contain a watermark. It consists of chopping an image up into a number of smaller subimages, which are embedded in a suitable sequence in a web page. Common web browsers render juxtaposed subimages stuck together, so they appear identical to the original image. This attack appears to be quite general; all marking schemes require the marked image to have some minimal size (one cannot hide a meaningful mark in just one pixel). Thus by splitting an image into sufficiently small pieces, the mark detector will be confused. The best that one can hope for is that the minimal size could be quite small and the method might therefore not be very practical. The current version of 2Mosaic can only read and produce JPEG files. We hope to implement other image formats in future versions. --- Usage: 2Mosaic [size] <file_name> 2Mosaic takes the name of a JPEG file as argument and produce several smaller images and an HTML file. All these files use the same basename. The default size of these square is 100x100 pixels. It can be changed by giving an integer between 16 and 100 as first argument. --- Example: 2mosaic 80 testimage.jpg produces testimage.html testimage1.jpg ... testimage<n>.jpg where <n> depends on the size of the original picture. --- Fabien Petitcolas <fapp2@cl.cam.ac.uk> <http://www.cl.cam.ac.uk/~fapp2/watermarking/image_watermarking/> This software is based in part on the work of the Independent JPEG Group. $Header: /2Mosaic/ReadMe.txt 4 30/10/98 10:44 Fapp2 $