Clients and friends alike regularly ask me to help them superimpose the image of a person onto another background.
The first problem is hair and the opacity between the hairs. Adobe Photoshop offers a tool called the “magic wand”. While this tool can get you a quick idea of the composition, you will soon realize the selection is rarely perfect, even if you “feather” the selection to soften the edges.
This tutorial will get you terrific results using alpha channels that have been available in Photoshop since it’s earliest days.
Thanks to Ed Layne for putting this together for me.
Good luck and good imaging!
1. Select the channel with the highest contrast (usually the blue channel).
2. Choose the magic wand tool and select the lightest area of the background.
3. Turn on the quick mask.
4. Use the pen tool to remove excess parts of the background from the extracted image.
5. Turn off the quick mask and select the inverse of your original selection (command+shift+i).
6. Choose the marquee tool and remove the edges of the hair from your selection.
Tip: Hold down the option key as you select with your marquee tool to subtract from the selection, hold the shift key to add to the selection.
7. Make a work path of the current selection.
8. With the marquee tool, select the outer edges that were removed from your path.
9. Turn off the work path leaving only the marquee area selected.
10. Create a new alpha channel.
11. Reselect the highest contrast channel (usually the blue channel) and copy the marquee area.
12. Paste your selection into the new alpha channel.
13. Choose the burn tool and select shadows in the adjustment palette with an exposure less than 18%.
14. Using the burn tool make the hair as close to solid black as possible.
15. Invert your selection of this area (command+i) and deselect (command+d).
16. Turn your work path back on and fill with white.
17. Paint areas of face and hair that were not burned to white.
18. Load your alpha channel as a selection.
19. Select your RGB channel and extract your image.
20. Once your image is placed into your new image temporarily turn on the stroke in your adjustment layers palette to find and erase any ghost pixels.