The nature of this optical illusion is to paint a grey scale image using only your eyes.
I originally saw an illusion that put an afterimage into a photo here and here. I also realized the importance of having a swappable background here, and found an illusion to add color to a B&W image here. All of these items combined inspired me to get off my butt and put this post together. I created another illusion here.
1. Pick an image with some color, preferably something everyone would recognize. For this demonstration I picked a nice public domain image of a Monarch Butterfly.
Photo courtesy PDPhoto.org
Create two images from this image.
2. First change the original image to gray scale using a program like Paint Shop Pro. Save the image by a different name. You may wish to lighten the image by changing it's brightness or gamma settings. This image works best with no changes to the gray scale image. But experiment with the final product to see what works best for the image you selected.
3. Next create a negative of the original image, also using a program like Paint Shop Pro. Save the image by a different name.
4. Now that you have your two images launch any basic animation program. I used Jasc Animation Shop (Paint Shop Pro's companion). This has an animation wizard. I just wanted to create a 2 frame animation. I placed the negative image in frame one and the gray scale image in frame two. I set a 10 second delay between frames 1&2 and a 1 second delay between frames 2&1 and chose to allow it to loop forever.
5. Walla, now you have your own illusion. Look at the image below. It will show the negative image for 10 seconds and the gray scale image for 1 second. The longer you look at it the more pronounced the effect.
I also provided a mouse over image below. Focus in the center for 30-45 seconds then move your mouse over and the image will swap to the grey scale image, but you will see the original image in all it's glory. While you hold your gaze on the gray scale image you may see the butterfly shift, even flutter as you attempt to keep the new colors in place.
A mouse over version for your viewing pleasure.
Stare at the center of the image for 45 seconds then move your
mouse over the image and view the grey scale image in full color.
© 2006 W. Anthony