While exploring and experimenting how shadows cast by separate red, green and blue lights could convey information I started experimenting with various colors and patterns, I became interested in seeing if I could hide simple information within geometric patterns. Can you see the text? If you view it through a red lens, it becomes apparent.

This exploration is a bit of a tangent from my experiments mainly because I got interested in what’s called steganography – hiding images within images.

Here are some resources that I have found

These experiments are using complex geometric patterns.

Results on screen:
Viewing the patterns with a red filter show the text clearly.
Hypothesis:
My hypothesis is that shining red light on the screen will produce no effect. Text will not be visible.
Results:
No change. Text is not visible. Probably due to backlit nature of screens. Since the blue text only shows because reflected light is negated.

Results printed:
Viewing the patterns with red filter shows the text clearly.

Hypothesis:
Shining red light on the printed paper will show the text.
Result

While exploring and experimenting with various colors and patterns, I became interested in seeing if I could hide simple information within geometric patterns. Can you see the text? If you view it through a red lens, it becomes apparent. Next is to shine red or blue light at the screen. My theory is that this won’t show the text because of the backlit nature of the computer screen.

The more complex the geometric pattern the more the text is hidden. So I looked for a more regular pattern with a more open design. The text is still hard to pick out but clearly visible when viewed through a red lens
Another pattern that hides a message.