Create Layer Mask Effects
The Apply Image command can also be used to create a layer mask from an image. Here’s how to use it to create an interesting border effect:
- Open the main image you want to use, as well as a black-and-white border image. (I chose one from Graphic Authority for this example.) Use Image > Rotate as needed to rotate one image, so both have the same orientation. Resize the images so that they’re the same size, as in the previous example.
- Choose Layer > New > Layer and click OK. To set the background color to black, click the new layer and press Control+Backspace (Command+Backspace on the Mac) to fill the new layer with black. Duplicate the image background layer by selecting it, choosing Layer > Duplicate Layer, and clicking OK. Drag the black layer between the two image layers.
- Click the top image layer and then click the Add Layer Mask icon at the foot
of the Layers palette (see Figure 4).
Figure 4 Use the Add Layer Mask icon to add a mask to the topmost layer of the image.
- Click the Layer Mask thumbnail and choose Image > Apply Image. From the
Source drop-down list, select the border image. Set the Blending mode to Normal.
Choose the Transparency channel from the Channel list if one is available, or
the Gray channel if no Transparency channel is shown. If necessary, check the
Invert checkbox to ensure that the border is in the correct position over the
image. The preview shows the result on the image (see Figure 5). Click OK to
accept these values.
Figure 5 When the border image is used as the source image for the layer mask, it creates a border-shaped mask for the image.
- A more advanced technique involves applying a mask to the border in the
Apply Image dialog. To do this, you would use the same settings as in the
previous step, but this time click the Mask checkbox. From the Source list,
select the image to use as a mask—in Figure 6, I used the image itself as
a mask. Select the Layer from the image and the Channel to use as the mask. In
this case, the Blue channel gave me the most interesting result.
Figure 6 To achieve an interesting effect, the grapes (target) image has been used to mask the border image at the time it’s applied as a layer mask to the grapes image.