Automatically Creating Layer Masks

You can automatically create layer masks by making a simple selection and using Paste Into. Here we'll replace the image in a cool dude's sunglasses with a sunset image of airplanes.

1. Open two photos: cool-dude.jpg and airplanes.jpg.

Start with the photo you want to use as the replacement area. In this example, we're using the photo of the airplanes

​2.Select the entire image of airplanes.jpg using Ctrl+A. Then copy the image with Ctrl+C.

3.     Now switch over to the photo of the cool dude. Use the Quick Selection tool to select the areas inside this sunglass lenses:

1. Use the Zoom tool tool to zoom into the sunglasses.
2. Select the Quick Selection tool.
3. Click the "Add to Selection" icon on the Options bar.
4. Click and drag the Quick Selection tool across the left-hand lens.
5. Drag the same tool across the right-hand lens.
6. If the selections spill over onto the face or the frames, press-and-hold the Alt key and click on those areas to subtract them from the selection. Make the brush size smaller to make small corrections.

4.   Choose Paste Into from the Edit menu. It will paste the airplanes image into the active selection: the dude's sunglass lenses. It makes sure the  airplane photo only shows in the lenses by automatically creating a layer mask for this new layer.

5.      Save the file as pasteinto.psd.
6.      Here's where it gets really cool. Select the Move tool. Click and drag the photo of the airplanes around. Find a good location for the planes in             the sunglass reflections.

7.   Now let's resize and warp the planes to simulate the curve of the lenses:

1. With the airplane layer still selected in the Layers palette, press Ctrl+T to transform the image.
2. Make the image smaller by holding shift while you drag one of the corner handles in a bit.
3. Right-click inside the transform box and select Warp.
4. In the Options bar, select Inflate from the Warp drop-down menu.
5. Press Enter to save the transformation.

8.     Drop the opacity of the airplane photo layer the better blend in with the glasses: in the Layers palette, change the Opacity to 80%. 
​9.     Save the file and close it.