Written by Steve Patterson. In this Photoshop Effects tutorial, we're going to learn how to turn a photo into a collage of squares.

It's a fun effect, and it's really easy to do, especially since most of the work is simple repetition, as we shall see.

Here's the original photo I'll be starting with:

And here's the image with the completed "Collage of Squares" effect:

As I said, most of the work is just repetition, so once you get "into the groove" with what you're doing, you won't even need to think about it. You can just have fun creating the effect.

Let's get started!

Step 1: Duplicate The Background Layer

With my image open in Photoshop, I currently have just one layer, the Background layer, which contains my original image:

I need to duplicate the Background layer, so I'm going to use the keyboard shortcut Ctrl+J (Win) / Command+J (Mac), which adds a copy of the Background layer in the Layers palette. Photoshop automatically names the copy "Layer 1":

Step 2: Add A New Layer Between The Two Layers And Fill It With White

We need to add a new blank layer between the two layers we currently have in the Layers palette. To do that, with "Layer 1" selected, hold down the Ctrl (Win) / Command (Mac) key on your keyboard and click on the New Layer icon at the bottom of the Layers palette. Normally Photoshop adds the new layer above the currently selected layer, but by holding down Ctrl/Command, this tells Photoshop to add the new layer below it instead:

I now have my new blank layer, "Layer 2", between the two other layers:

Just a quick note before we continue.... We're going to end up with lots of layers by the time this effect is finished, and normally that would mean we'd definitely want to make sure we're naming our layers as we go. In this case though, you'd probably drive yourself mad trying to come up with descriptive names for each layer, so unless that sort of thing appeals to you, I wouldn't worry about naming your layers when creating this effect. Generally speaking though, naming layers is a habit you should get into.

Having said that, let's continue. We need to fill this new layer with white, since we're going to use white as our background color for the effect, so press the letter D on your keyboard to reset your Foreground and Background colors, which makes white your Background color, and then with the new blank layer selected in the Layers palette, use the keyboard shortcut Ctrl+Backspace (Win) / Command+Delete (Mac) to fill the layer with white.

You won't see anything happen in your Document Window, since the copy of the Background layer is blocking "Layer 2" from view, but if you look in the Layers palette, you'll see that the thumbnail preview for the layer is now filled with white:

Step 3: Drag Out A Square Selection Around Part Of The Image

I'm going to click back on the copy of my Background layer, "Layer 1", in the Layers palette to select it. Then I'm going to grab my Rectangular Marquee tool from the Tools palette:

I could also press M on my keyboard to quickly select it. Then, with the Rectangular Marquee tool in hand and "Layer 1" selected in the Layers palette, I'm going to drag out a square-shaped selection inside the image. I'll drag out a square around the boy's face on the right:

In order to constrain the selection to a perfect square, hold down Shift as you drag.

Step 4: Add A Layer Mask

Once you have your square-shaped selection, and again making sure that "Layer 1" is selected in the Layers palette, click on the Add A Layer Mask icon at the bottom of the Layers palette:

This will add a layer mask to "Layer 1", and because I had an area of the image selected when I clicked the "Add A Layer Mask" icon, Photoshop will use that selection to create the mask, meaning that only the area of the image that was inside the selection - the boy's face - will remain visible in the Document Window. The rest of the image will be hidden from view, revealing the white-filled layer below it:

Step 5: Unlink The Layer Mask From The Layer Contents

If we look at our Layers palette once again, we can see the layer mask that's been added to "Layer 1". The mask is filled with black, except for the small square area that's white, which is the area around the boy's face that's showing in the Document Window. If you look closely, you'll also see a small link icon between the layer thumbnail and the mask thumbnail:

When that link icon is visible, it means that the contents of the layer (the image) and the layer mask are, well, linked. If you move one, you move them both. That's not what we want. We want to be able to move the mask without moving the image. In order to do that, all we have to do is click on that link icon, which will cause it to disappear, at which point the layer mask can be moved independently of the layer contents. I'm going to click on the link icon to remove it:

Step 6: Add A White "Outer Glow" Layer Style To The Mask

In order to be able to see the edges of the squares as we're creating the effect, I'm going to add an "Outer Glow" layer style to the mask. First, I'm going to click directly on the layer mask's thumbnail to select it. I can tell it's selected when it has a highlight box around it. Then, with the mask selected, I'm going to click on the New Adjustment Layer icon at the bottom of the Layers palette:

Then I'll select Outer Glow from the list that appears:

This brings up Photoshop's Layer Style dialog box with the Outer Glow options in the middle column. By default, the Outer Glow layer style uses a yellowish color. I want to change it to white, so to do that, I'm going to click directly on the Outer Glow's color swatch:

When I click on the color swatch, Photoshop's Color Picker appears. I'm going to choose white in the top left corner:

Then I'll click OK to exit out of the Color Picker. My Outer Glow color is now white.

I'm going to leave all the other options for the Outer Glow alone and just click OK at this point to exit out of the Layer Style dialog box. The white Outer Glow will be added to the layer mask. We won't be able to see it in the image just yet because it's a white glow against a white background, but we'll see it once we start adding more square sections to the image, as we're about to do.