In order to make your own CTRL+A images, first you have to understand how they work. Once you do, the instructions will be much clearer. You'll also need a graphics program, such as Photoshop, to create the images.

Make Your Own

How They Work

When you select an image in Internet Explorer on a PC, the image appears tinted.

Plain Image Selected Image
plain image selected image

This tinting effect is caused by a grid that is placed over the image. Think of a checkerboard, where each square is just one pixel. If you remove all the red squares and make them transparent, what you've got left is the tinting grid (except it's a dark blue color instead of black).

The Grid (against my background) Close-Up View of the Grid
grid grid zoomed

The basic idea behind the CTRL+A pictures is that both images are always present and visible in the original image. Using our checkerboard analogy, all of the black squares would contain pixels from the main image, and all of the red squares would contain pixels from the "hidden" image. However, the "hidden" image is barely able to be seen, if at all. So why is that? The reason is the choice of color levels. The image is subdued by altering its color levels to make it blend in with the main image. When highlighted, all the pixels from the main image are covered up, leaving only the pixels from the "hidden" image to be seen.

Let's Walk Through It

The first step is to choose two images. The main image should have enough going on in it to camouflage the image you want to hide.

Main Image Image to be Hidden
main image image to hide

In Photoshop, create 3 layers. Place the main image on the bottom layer, and place the image to be hidden on the middle layer. For the top layer, you'll have to make a grid (You can download a sample in Photoshop format here). Make sure the top left pixel is not transparent in your grid.

photoshop

Now, select the middle layer, then hold down the CONTROL key and click on the top layer. Because your top layer is the grid, this will select every other pixel in your middle layer. Then hit the delete key to erase all these pixels.

Hide the grid layer. Your image should look something like the image below.

raw composite

You're almost done! All that remains is to camouflage the middle layer to blend in with the main image. Do this by selecting the middle layer and adjusting the ouput levels (hit CONTROL+L in Photoshop on Windows or go to the Image-Adjustments-Levels... menu item). This part is the trickiest. You'll have to play around with the levels to get the best results. You can also alter the brightness/contrast of the middle layer to achieve the desired effect.

Once you think you've got it right, you can test your image by making the grid layer visible again. You should be able to see the "hidden" layer, just as it will appear in a browser. If it's too faint, back up and try adjusting the levels again. If you can't seem to get it, maybe your main image doesn't have enough going on. Try choosing a main image that doesn't have large solid colored areas. Once it looks good, save your image as a gif and you're good to go!

Now, you should have your very own CTRL+A image. Congratulations!

finished product

View the Examples