TeamPhotoshop
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Tutorials

Creating a mask and painting on a mask

Oct 18th 2005
Creating a Mask: Face

1.
Selections. selections, selections.

When you want to alter a portion of an image or create a composite image, you need to select an area. Like most tasks, Photoshop offers many possible ways to do this. Probably the most precise way to make a selection is to paint a mask.

I started out using the lasso tool to draw a large marquee around the area you want to select. Now we enter Quick Mask Mode. Near the bottom of the tool bar are the two mode buttons, Standard and Quick Mask. Quick mask mode (click the button on the right) lets you edit any selection as a mask. Now you can use almost any Photoshop tool or filter to modify the mask. For example, you can use a filter to distort the edges of the selection. You can also use selection tools, because the quick mask is not a selection. I'm going to use the Airbrush tool to modify the edge of the mask so it fits exactly to the edge of the woman's profile.
You can, of course, create the mask entirely in Quick Mask mode, but making the lasso selection first for me is a quick shortcut, so I don't have to paint a huge area. Depending on how close to the edge of your shape you draw a selection, and the clarity of its edges, you might want to feather your marquee selection so it's not completely hard.

Double-click the Quick Mask mode button to see the Quick Mask Options dialog. Color differentiates the protected and unprotected areas. You can change the default color of the mask here (I chose a Magenta), and you can decide how opaque the mask should be. 20 or 30% seems pretty good and allows you to see the underlying image enough.

 

 2.
If we take a close look at a couple of areas in my image, you'll see why I chose to make a mask to select the woman in my image.

On the left, here you can see that the area where the woman's profile meets the background is very indistinct. The blurriness of the farthest set of eyelashes is an extreme example of this. If I used a marquee tool, to select the woman, I could of course try all different feather settings in different areas to arrive at just the right selection. But this is going to be much easier. By painting with various brushes and opacities, I'll be able to see exactly what and how much is selected.

In the lower image, You see a part of her hand and her lower lip. Notice the difference in hardness of edge. The hand is more in focus, while below her lip is more blurry..

 3.
My marquee selection in the image to the left represents (for your benefit) the size of brush I'm going to start out with in relation to my image size. I'll be using a soft-edged 21 pixel brush, and the opacity of the airbrush will be set at about 80%. (You can press the number keys on your keyboard to quickly change opacity. Hitting the 9, for instance changes my opacity to 90%).

Here I'm painting with the Background Color (white), so what happens is, the mask gets erased where I paint. Painting with the Foreground Color (black) adds to the mask. Use the X key as a shortcut to swap the position of the foreground & background colors. That way if you accidentally paint to far, hit the X key and use the opposite color to fix the area.

Think of the painting of the mask in two steps. First, I'll use a smaller brush at a high opacity to perfect the edge of the mask. Later I'll use larger brushes at lower opacities to give the edge the blurry quality where needed. You can see (to the left) how my mask's edge looks after I use the small brush.

 

 4.
I'd like you to see how I'm working at this point. You can see a scaled down screenshot of a portion of my mammoth 21 inch monitor there to the left. Notice I chose New View from the View Menu so I could see from two different perspectives how I was doing. When you're zoomed in really close as you need to be, you can sometimes go a bit to far, or not enough, with what you're doing. What you see here are two views of the same file. Changes made in one window are immediately reflected in the other. Keeping the window on the left zoomed out for reference, makes sure I don't lose site of the "Big Picture."

 

 5.
Now it's time to use a larger brush to soften up the edges. I'm using soft brushes ranging in size from 45 to 65 pixels. In the image at left here, I've drawn a marquee to represent the size and position of my brush. Now I've got the opacity set at 10 or 20%, so I'll venture near the edge of the mask, gradually depleting the edge's hardness.

Notice the difference in the edges between the two lower images at left. In the upper one, you see the edge on the forehead after I painted with the small brush at 80%. Below that, you see the much softer edge I made using the larger brush at 10% opacity.

 

 6.
After I finish painting with the larger brush, I exit Quick Mask Mode. I click on the button on the left and enter Standard Mode. When you leave Quick Mask mode, the unprotected areas become a selection. Then I choose Select: Inverse and jump back into Quick Mask Mode. Now the layer mask is over the woman. This gives me another view of the mask and now I can check out the opacity of the edge of the colored mask in relation to the blurriness of the edge of the woman's face. I'll do a little touch up work if needed as I closely examine what I created earlier.

 7.
To the left here, I've got the image showcasing the difference in edge clarity between the hand and face. Below it you see a magnification of that point where the hand's outside edge meets that of the chin. I cranked the opacity on my layer mask way up here so you could easily notice how blurry and soft the edge of the mask is over the area below her lip, compared to the harder edge on the mask of the hand.
 8.
When I'm finally finished painting, I leave Quick Mask mode and go back to Standard, and my mask becomes a selection. You can see my beautifully painted mask has disappeared and suddenly soft areas such as around the eyelashes look like they're not properly selected. Don't panic here! Photoshop still knows the exact feather and opacity that the mask had, but it has to display the marquee somewhere. So in areas of lower opacity, the selection edge will appear closer to the area of the mask that was more opaque.

Now I'll save my selection. I'd hate to have to ever do this masking job again. Choose Select: Save Selection.... Check out your Channels Palette. You'll see the selection forever save there as an Alpha Channel.

In Photoshop, channels store an image’s color information. In addition, channels and masks store selections. Alpha channels store selections as 8-bit grayscale images and are added to the color channels in an image. An image can have up to 24 channels, including all color and alpha channels.
 9.
Any time I want to I can choose Select: Load Selection... and manipulate, adjust, or alter specific parts of my image. Here I've simply adjusted the Hue/ Saturation of the image's background.

Once you manage to create great layer masks, you'll seldom go back to drawing intricate selections with the lasso. Once you get a good selection, you can start altering or compositing images.
 10.
Let's talk about image content, or the effect or meaning an image has on a viewer. You can use altered or combined images you create in Photoshop to elicit a specific mood - which can be totally different from the content of the original image(s). For me, the original image of the woman is a study in the striking handsomeness of this woman, or of women, or people in general. Above, where I gave the background a blue tint, the image seems to take on a somber tone, and the woman's pose seems slightly sad. If I stick in an image (right) of an hourglass (which I blurred appropriately), now the viewer might assume she's worried about time- getting older; biological clock; or who knows what?

But we've gotten off topic. Or maybe we haven't. Making selections can be challenging and rewarding, but I don't think I'd ever call it fun. The fun part comes when you actually do something with the selected areas.

Happy Image Editing!