by Chad Neuman

Photo mosaics are photos comprised of many other photos. Photos are places in square or rectangle areas of the image, almost like pixels. Each photo has a certain hue that matches what the part of the master photo should be. Here’s a quicker way than trying to find photos that match specific parts of a photo.

Instead of having the hue in each photo represent that area of the master photo, we’ll have the color of the master photo show through to the tiled photos. And instead of having to find dozens or hundreds of photos, we’ll just need a few. This technique can be used for advertisements, personal photos, promotional brochures, annual reports, and other creative designs.

Step 1
Open up a photo of what you want to be the master photo. You may try having a few people’s faces make up another person’s face, or photos of nature making up another photo of nature. For my example, I am going to have different coastal nature photos to comprise a photo of a woman’s face. Be sure to use the Crop tool to crop closely along the face.

Step 2
Next, get four photos you’d like to use as the texture of the master photo. We could use two photos and checkerboard them, but let’s use four for this example. As you can see, these photos are quite large and need to be made much smaller to be the tiles.

Step 3
Select the Crop tool and up on the Options palette, set the Height and Width to 25 px, 50 px, or 75, depending on how big you want the tiles to be. Also change the resolution preset to what the resolution of the master photo is. For my example, it’s 72 pixels per inch. Note: Be sure to set the Width and Height to pixels, otherwise it may enter inches by default and the image will be too large.

Step 4
Next, click-and-drag to crop all four photos to the preset size. Either press Return (PC: Enter) or double-click inside the crop area after drawing the crop. Then multiply whatever width and height you set it to by two, and then create a new file with this for width and height. Since I set mine to 75 pixels each, my new file will be 150 pixels by 150 pixels. Make sure the resolution is the same as what the preset was set to. Name it tile.

Step 5
Next, select the Move tool and click-and-drag the four photos onto the new file to make a checkboard pattern. After moving, try the keyboard arrows to fine-tune the placement. Each new placed photo will be on its own layer.

Step 6
Desaturate the image by going to Image>Adjustments>Desaturate for each layer, or merge the layers first by pressing Cmd-E (Ctrl-E) and then desaturate. Go to Edit>Define Pattern and name it something appropriate, such as “beach photos” or “tile.”

Step 7
Make sure there are not a lot of blank pixels, or too bright pixels, in the tile. This can cause the final result to look funny. I noticed the upper right hand photo had too much brightness on the top so I replaced it with another beach photo.

Step 8
Next, open the original master photo. Click the Create New Layer icon on the Layers palette. Go to Edit>Fill and select Pattern. Change the Custom Pattern to the pattern we just created. Make sure Mode is Normal and Opacity is 100%.

Step 9
This will fill the second layer with the pattern. In the Layers palette, change the Layer Blending Mode of the top layer to Overlay. There we have it, a photo mosaic!

Bonus Step
Let’s say you want to create a photo mosaic that actually uses the original hues from the tiled photos to make up a larger photo, instead of having the hues overlay onto the tiled photos like in this technique. You’ll need many more photos with varying hues and patterns and a computer program to do that, unless you have a lot of time on your hands. PC users go to http://www.andreaplanet.com/andreamosaic/ and MAC users go to http://homepage.mac.com/knarf/MacOSaiX/Download.html and download the program to do this. There are some pretty neat examples, including Van Gogh’s starry night consisting of many different photos.