1. IMAGE FORGERY
1. DEFINITION AND HISTORY
2. TYPES OF IMAGE FORGERY
A. IMAGE RETOUCHING
B. IMAGE SPLICING
C. COPY AND MOVE ATTACK

2. 
Image Forgery is not new. History has recorded that it happens as
early as the 1840s. Hippolyta Bayard, the first person to create a
fake image as recorded by history, is famous for a picture of him
committing suicide (see picture on the left). It all started as an act
of frustration because he had lost the chance of becoming 'the
inventor of photography' to Louis Daguerre. Daguerre patented a
photography process earlier than him and owns all the glory [1].
 Digital Image Forgery does not differ very much in nature
compared to conventional Image Forgery. Instead of using
photograph, digital image forgery deals with digital image. The
process of creating fake image has been tremendously simple with
the introduction of powerful computer graphics editing software
such as Adobe Photoshop, GIMP, and Corel Paint Shop, some of
which are available for free.
 There are many cases of digital image forgery. All of these cases
can be categorized into three major groups, based on the process
involved in creating the fake image. The groups are Image
Retouching, Image Splicing, and Copy-Move Attack.

4.  Image Retouching can be considered to be the less
harmful kind of digital image forgery. Image
retouching does not significantly change an image,
but instead, enhances or reduces certain feature of
an image (see picture below). This technique is
popular among magazine photo editors. It can be
said that almost all magazine cover would employ
this technique to 'enhance' certain features of an
image so that it is more attractive; ignoring the fact
that such enhancement is ethically wrong.

6.  This technique is more aggressive than image
retouching. Image Splicing is a technique that
involves a composite of two or more images which
are combined to create a fake image. In the picture
below, 'the shark' is copied to the base image
(helicopter rescue). The base image is first flipped
horizontally before the shark is pasted to create a
more convincing (and not to forget dramatic)
picture of a helicopter rescue.

8.  Copy-move attack is more or less similar to Image Splicing in
view of the fact that both techniques modify certain image
region (of a base image), with another image.
However, instead of having an external image as the
source, copy-move attack uses portion of the original base
image as its source. In other words, the source and the
destination of the modified image originated from the same
image. In a copy-move attack, parts of the original image is
copied, moved to a desired location, and pasted. This is
usually done in order to conceal certain details or to duplicate
certain aspects of an image. Blurring is usually applied along
the border of the modified region to reduce the effect of
irregularities between the original and pasted region [2]. The
picture below shows a sample image that has been tampered
using copy-move attack (left) and its original (right). Notice a
repeated smoke pattern on the left image.

10.  There are many ways in which you can secure your home and
business against crime and avoid becoming another statistic.
 Established in 1992 image security offers comprehensive range of
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11. The Internet is a great way to show your photographs to the world.
Putting images up on a web site is child’s play compared to hanging
a gallery show or publishing a book. But what is to stop an
unscrupulous web site visitor from stealing your images? In truth, all
the images that are seen by your visitors are already copied and
stored in their computer’s browser cache. But there are still
effective, low cost ways of preventing their misuse.

12. Adding Your Copyright as a
Text Layer
This is the easiest and most effective way to protect your
images. Placing the copyright symbol and your name directly in
an image tells everyone that your work is copyrighted. We
recommend including your web site URL (or phone number if
you don’t have your own web site) so anyone who prints out or
copies your picture can easily find you in the future. This turns
every copied image into an advertisement for you.
Each graphics program handles text differently, but look for
the Text Tool on the tool bar within your program. Use an easy
to read font like Arial in a small point size. If your image has
light and dark areas that make text hard to read you can select
the area behind the text and reduce its contrast.

13. Size and Compress Your
Images Properly
There are two benefits to this approach. Smaller images will
reduce both the quality of a printout and will also speed page
load time. Keep your image size to under 450 pixels on the long
dimension. If anyone were to print it, it would either print small,
or if forced to be a larger print the image will look pixilated
(pixels will spread out). Next, compress your images until they
just begin to show artifacts. This will help them load faster, and
further reduce the chance they will be misused. We recommend
using one of the side by side compression tools that give you a
visual confirmation of how much you can compress the image
before it starts to visually degrade. Photoshop's "Save For Web"
(also available in Photoshop Elements) is our tool of choice.

14. Image Slicing to protect
your images
Using your graphics program, you can slice your pictures into
two or more slices. Right clicking and saving would only get
the view the part of the picture that was clicked on. And the
browsers cache will only have fragmented bits of images in it.
The individual image parts, which are really separate,
pictures loading into different cells within the same table, are
joined in the HTML when viewing the image on the web. An
added benefit of slicing is shorter load time when you
optimize each slice individually. In a program like
ImageReady (part of Photoshop 6), different parts of the
same image can be optimized as Gif’s or Jpeg’s

15. Mouseover image swap
Another bit of JavaScript code can cause one image to replace another
when the user’s mouse passes over it. The replacement image can
include a warning about not copying your images.
Table Background and
Transparent GIF
This is a bit more complex, but quite effective. First create a table exactly
the same size as the image you want to protect. Next, set the image as
the table background. Create a transparent GIF with a similar name and
exactly the same pixel dimensions as the original image and insert it into
the table. If someone tries to copy it by right clicking on it, all they get is
the transparent GIF