For those of you of the artistic persuasion, you might be using Photoshop or GIMP to color your scanned drawings. Fortunately, putting the line art in a transparent layer is very easy with this slick technique.
This technique is a standard for any Photoshop user’s bag of tricks, and one that is useful lots of different situations. It can work on rough drawings, tight, inked line art, or even layers you’ve accidently drawn into or merged while working. Keep reading to see our simple technique.
Removing the Background In Photoshop (GIMP Friendly Instructions)
While you can work with any number of layers, we’re going to assume you’re working with a single background layer for your scanned drawing.
The image can be in either Grayscale or RGB. Check the channels by clicking on the Channels Panel tab, available by default in Photoshop’s “Essentials” workspace.
Press to select the entire canvas. Then to copy the single background layer to the clipboard.
Jump to your Channels Panel and create a new Alpha channel by clicking on the icon in the bottom of the panel. Paste it by pressing with the new channel selected, as shown.
If you have loads of gray pencil marks or dirty smudges in the artwork, you can eliminate them here by pressing to open the levels tool. Moving the rightmost slider towards the left side will white out all of the lightest grays and highlights.
Optional: You can also turn this Alpha channel into pure line art (black and white with zero shades of gray) with a Threshhold filter. In Photoshop, you can find this by navigating to Image > Adjustments > Threshhold. GIMP has it under Tools > Color Tools > Threshold.
With your Alpha channel looking perfect, you can + Click on it to select all of the black areas in the image.
If your line art isn’t the part that is selected, you may have to employ a quick to invert the selection. Ignore this step if your image is selected correctly.
Jump back to the layers panel and create a new layer by pressing or clicking on the located at the bottom of the panel. Make sure the new layer is selected as shown above.
Fill your new layer by selecting Edit > Fill. Set your Contents to Use: Black as shown above. Hit OK when you’re finished!
Your line art is now in a separate layer. Turn off the background layer to better see your results.
You’re now free to do whatever you please with your drawing, whitespace now removed.
You can return to your channels panel to remove the temporary alpha channel at anytime by selecting the now unnecessary channel and clicking the at the bottom of the panel.
And that’s all there is to it—you’re now free to do most anything you can imagine to your line art layer.
Enjoyed our technique? Or do you have one of your own, honed from working on a million of your own drawings? Tell us about your experience in the comments, or email us your questions at firstname.lastname@example.org, where they may be featured on How-To Geek in an upcoming graphics article.
Image Credit: Doctor Slump Illustration by Akira Toriyama, used without permission, assumed fair use.