The case of the vanishing image

[Wilhelm Sanke]

While tinkering with my "Imagedata Toolkit" - scheduled for release in 
May - I came across an interesting phenomenon unknown (at least) to me.

After reducing the number of colors of an image with a specific 
algorithm to 512, 64, or 8 colors *and* duplicating the imagedata after 
that, the image will suddenly disappear - after one click on the 
"duplicate..." button with 8 colors, two clicks with 64 , and three 
clicks for 512 colors.

The image then slowly reappears after more clicks on the "duplicate" 
button (six clicks for 8 colors, four clicks for 64, and three more 
clicks with 512 colors).

Maybe this could be used to hide information in *invisible* images or to 
hide and retrieve such images themselves.

I have uploaded a sample stack "Vanishing Image" to my website 
<http://www.sanke.org/Software/VanishingImage.zip>

The stack contains a photo to test the feature and a few more 
unprotected algorithms that may provide some insight into the basics of 
imagedata manipulation, including compressing imagedata and storing them 
in custom properties or export (and reimport later) to external files or 
PNG-images.

The "Imagedata Toolkit" will comprise about 250 different efffects for 
"creative" imagedata handling. A preview of what will be possible with 
the "ImageData Toolkit" is available at <http://www.sanke.org/MetaMedia> 
page "Imagedata Art".


--Wilhelm Sanke
<http://www.sanke.org/MetaMedia