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ImageSafe is for those who have an image they want people to see
but not in a form
that can be easily copied. To do this the product encapsulates webpage images in a Java applet for viewing.
- Images can be viewed using all browsers with Java support
- Support for old browsers going back to Netscape 4.06 and Internet Explorer 4.0
- Images can't be retrieved from the cache or server nor can they be right clicked and the applet can be prevented from running
- A single HTTP request fetches the applet and image with a total download overhead typically around 2.9K
- A line of text or second image can move across the main image to frustrate screen capture
- Animated GIFs as well as static GIFs and JPEGs can be protected and this can be done in batches
- Batches of many thousands of images can be processed at once
- A view-by date can be specified after which the images will no longer appear
- Images can link to other webpages like any other webpage image
- ImageSafe can password protect images without requiring any CGI programming
This is done by setting a password on the image and by getting ImageSafe to generate a special file, about
1K in size. This file could be e-mailed to authorized viewers of the image but it must exist on the viewing PC's
disk for the image to be seen
- Try before you buy!
Links for ImageSafe are:
What about screen capture?
Screen capture by a user can be done in a second and
it's not possible to prevent the saving of what's on the screen despite attempts to
disable key sequences.
The best way to frustrate
screen capture is to animate the image in some way. Just encoding the image in an applet is little deterent on it's own
although animated GIFs are the exception since they are already moving. If you are just interested in having a static
watermark over your image then use H2Omarker.
To get maximum protection from ImageSafe it's recommended that the following options be employed:
- The "originating server prefix" should be specified so that applets won't run locally
- Moving text or a moving second image should overlay the main image to
frustrate screen capture.
ImageSafe and HTML editors
A lot of page authoring is now done with HTML editors like Frontpage.
Some users may find it tricky to cut and paste the HTML of
an ImageSafe applet so ImageSafe provides the option for the correct HTML to be put directly into the system clipboard.
Once there, clicking the Windows right mouse button and doing a paste operation can move the HTML directly into the HTML
editor's "insert HTML" dialog.
ImageSafe and watermarking
There is no problem using a watermark such as Photoshop's Digimark or
H2Omarker and ImageSafe together. This can provide an additional
level of digital rights management (DRM). The image that goes into ImageSafe is the image
that comes out. For more on watermarking and it's problems
go to Fabian Petitcolas's watermarking page at Cambridge Uni.
A note about browser caches
If you protect an image with ImageSafe and run the same image through ImageSafe again, perhaps because
you registered the product or changed an option, you may get a "Null pointer exception" message when you
look at the new applet on your local PC. The reason is that the browser is retrieving the old applet out of the
cache so the cache should be cleared to fix the problem.
ImageSafe is NOT a panacea for copy protection.
The product can however, make it extremely difficult to get hold of a clean copy of an
image. It should be noted that if a moving overlay image is used with Imagesafe and the image is too small it may be that
screen captures could be made at different times
and the screen shots lined up in an image editing program and the overlay image edited out.
If a line of moving text is used (particularly one with no spaces) then it becomes
virtually impossible to remove this no matter how many screen captures are made.
- The other weakness concerns download times. Clearly there is a small extra amount of data to download with the image
however perceived download time can be higher because all the data has to download for the image to appear. In the
case of Netscape all the ImageSafe applets on a single page have to download completely before any will appear. This means
it is not appropriate to have many images on a single page unless you know your site visitors have a fast connection.