Login or Register to Ask a Question and Join Our Community

learn linux and unix commands - unix shell scripting

Image forensics

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
# 1  
Old 01-01-2010
Image forensics
An interesting analysis of a graphic recently used by Victoria's Secret in their advertising.  This gives chapter and verse of the techniques used, and results obtained, demonstrating the ability to determine if an image has been altered, and even which parts of an image have been modified, and how.

I find this particularly interesting because of the apparently widely held belief that steganography is "undetectable" without comparision to the original image.  Most of the "Photoshop disasters" are glaringly obvious to the naked eye.  As this demonstrates, analysis and detection of modification is easily accomplished, even when the differences are not apparent to the human eye.  (Well, except for the straps.  That was pretty stupid ...)

Image
Image

More...
Login or Register to Ask a Question

Previous Thread | Next Thread

2 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

matching image files to create one image

Hi, I have two sets of image files. Both sets have names A to Z but set 1 ends with .cdt.png and set 2 ends with .matrix.png. I want set 1 to match with set 2 if the names match (i.e. A.cdt.png will match with A.matrix.png) and with the convert image tool (program for images), it will merge the... (6 Replies)
Discussion started by: kylle345
6 Replies

2. UNIX for Advanced & Expert Users

Create an Ignite image on tape from Online IgniteUX image

Hi, (HP-UX 11.11) I need to create a tape image of an igniteUX image created on our igniteUX server. That is to say. I have a "Online" image of the igniteUX of the targeted system but I now need to copy it to a useable TAPE (igniteUX) image so i can build an other server from it that is not... (3 Replies)
Discussion started by: Andrek
3 Replies
Login or Register to Ask a Question

LEARN ABOUT DEBIAN

image::seek

Image::Seek(3pm)					User Contributed Perl Documentation					  Image::Seek(3pm)

NAME

       Image::Seek - A port of ImgSeek to Perl

DESCRIPTION

	   use Image::Seek qw(loaddb add_image query_id savedb);

	   loaddb("haar.db");

	   # EITHER
	   my $img = GD::Image->newFromJpeg("photo-216.jpg", 1);
	   # OR
	   my $img = Imager->new();
	   $img->open(file => "photo-216.jpg");
	   # OR
	   my $img = Image::Imlib2->load("photo-216.jpg");

	   # Then...
	   add_image($img, 216);
	   savedb("haar.db");

	   my @results = query_id(216); # What looks like this photo?

	   remove_id(216); # Just remove id from database.

DESCRIPTION

       ImgSeek (http://www.imgseek.net/) is an implementation of Haar wavelet decomposition techniques to find similar pictures in a library. This
       module is port of the ImgSeek library to Perl's XS. It can deal with image objects produced by the "Imager" and "Image::Imlib2" libraries.

EXPORT

       None by default, but the following functions are available:

   savedb($file)
       Dumps the state of the norms and image buckets to the file $file.

   loaddb($file)
       Loads a database of image norms produced by savedb

   cleardb
       Clears the internal database. Note that "loaddb" will load into memory a bunch of data that you may already have - it will duplicate rather
       than replace this data, so results will be skewed if you load a database multiple times without clearing it in between.

   add_image($image, $id)
       Adds the image object to the database, keyed against the numeric id $id. This will compute the Haar transformation for a 128x128 thumbnail
       of the image, and then store its norms into a database in memory.

   remove_id($id)
       remove id from database, and you should "savedb" to save the changed database.

   query_id($id[, $results))
       This queries the internal database for pictures which are "like" number $id. It returns a list of $results results (by default, 10); a
       result is an array reference. The first element is the ID of a picture, the second is a score. So for example:

	   query_id(2481, 5)

       returns, in a shoot I have, the following:

		 [ 2481, -38.3800003528595 ],
		 [ 2480, -37.5519620793145 ],
		 [ 2478, -37.39896965962   ],
		 [ 2479, -37.2777427507208 ],
		 [ 2584, -10.0803730081134 ],
		 [ 2795, -7.89326129961427 ]

       Notice that the scores go the opposite way to what you might imagine: lower is better. The results come out sorted, and the first result is
       the thing you queried for.

SEE ALSO

       http://www.imgseek.net/

AUTHOR

       Simon Cozens, <simon@cpan.org> Lilo Huang, <kenwu@cpan.org>

       All the clever bits were written by Ricardo Niederberger Cabral; I just mangled them to wrap Perl around them.

COPYRIGHT AND LICENSE

       Copyright (C) 2005 by Simon Cozens, 2008 by Lilo Huang

       This library is free software; as it is a derivative work of imgseek, this library is distributed under the same terms (GPL) as imgseek.

perl v5.14.2							    2008-02-09							  Image::Seek(3pm)