Displacement Maps, which are quick and easy to prepare, are very useful when you want to apply a texture or another image to an image where you want to have the applied image or texture follow or conform to the contour of the image it is applied to.
Step 1 - Prepare the Displacement Map:
The task here is to create a grayscale or multichannel (grayscale) psd image which will be used by the Displace Filter a little later. You want this map to have a good amount of contrast. You can accomplish this a number of ways but I typically use the following:
a) Convert the image to grayscale using Channel Mixer, Desaturate, or whatever you favorite method may be. Then save this grayscale image as a .psd file.
b) Examine the individual channels (in any color space) and choose the one with the highest contrast. Then from the little triangle in the Channels Palette choose Channel>Duplicate. When the dialog box comes up, select from the pull down menu "NEW DOCUMENT", name it and click OK.
PS will then create a new grayscale document which will automatically be in Multichannel Mode. All you need to do is save this file as a .psd. I would recommend that you insert the words "Displacement Map" at the end of your file name so you can locate it easily later. Now close the displacement map file as you no longer need it on your desktop.
NOTE 1: For subsequent experimentation, you should try a levels adjust to the map before saving it in order to make it more contrasty. This will usually accentuate the transitions and produce a better displacement map. However you do not want to overdo it.
NOTE 2: With some background images you will find they have too much very fine detail which can produce jagged edges in the mapping process. You can negate the jaggies by slightly blurring the displacement map prior to saving it. I find that application of
PS Filter>Noise>Despkle once or twice does a nice job of softening the map.
Step 2 - Image Prep:
Go back to your original image. Make a selection of the narea to which you plan to apply a texture or image. For example Nancy, in your image, I selected the fabric. Save the selection (which will be loaded at the end) and deselect it before continuing.
Step 3 - Add the new layer:
Create a new layer. If you plan to apply a texture, fill it with a color and you can use the Filter>Texture>Texturizer. In the example above, I added a solid yellow color and applied a brick texture. In the sample below, I pasted the US flag into the layer. The new layer can be completely filled as in the example above, or can be partially filled as in the example below where I centered the flag vertically to cover Amber's face with a small amount of overlap.
Step 4 - Application of the Map:
With the top layer active, go Filter>Distort>Displace. When the dialog box comes up leave the default values (10, 10, Stretch to Fit, Repeat Edge Pixels). Depending on the image resolution (this was set to 72 dpi) you may need to try more or less, but 10 is a good starting point. You can also specify a % rather than a number of pixels.
Click OK and another dialog window will appear in which
PS is asking you to direct it to a Displacement Map (must be .psd). Direct it to the displacement map you created earlier and click open.
Voila, you should now have a top layer which is distorted to fit the contour of the background layer BUT it won't necessarily be to well defined.
Start by changing the Blend mode to Darken or Multiply This usually gets you what you need / want . Next try Normal mode but start to lower the opacity. Then try other blending modes as you can get some really weird and creative effects. In the example below I used Darken whcih made the white of the flag become invisible.
By now you have noticed that the entire image has been affected by the top layer which is probably not what you want. Remember that selection you saved earlier?? Select>Load Selection and load the selection you prepared. Then Ctrl+Shift+I to select the inverse. Hit Backspace to delete all of the background that you do not want to be affected.
Finishing Touches:
In the example below, when I applied the flag, it fit Amber's contours nicely but it also ran thru her eyes and accross her lips. I selectively erased those areas on the applied layer.
I hope you find displacement maps fun and useful.
Regards, Murray