I would like to scan some old illustrations and take the color out, leaving only the black pen lines (to make coloring book pages for my students). I don’t want the blues and reds changed to grey, I want them removed. Is there a commercially available program that will do this?
Googling didn’t turn anything up as far as freeware, but you can achieve this in Photoshop by going to Image > Adjustments > Black & White, and cranking all the color sliders to max or close to it. (You can probably also do it in the GIMP, but I don’t know the commands off the top of my head.)
Here’s a quick-and-dirty example using a Superman drawing I pulled from an image search.
Before: http://images1.wikia.nocookie.net/__cb20100819014815/superman/images/7/72/Superman.jpg
After: http://img191.imageshack.us/img191/1121/examplejty.jpg
If that’s what you were going for, and you don’t have access to Photoshop, I’d be glad to help out if you want to send the images over. My email’s in my profile.
Photoshop Image > Mode > Grayscale
is the simplest and leaves a much smaller file.
Backup your original first.
If you can’t afford Photoshop, GIMP can probably do it too.
Thanks, I’ll probably go w. Photoshop!
To clarify, Grayscale converts colors to shades of gray, and is by far the simplest option if that’s what you need. If I understand the OP correctly, he doesn’t want grays, but wants everything that isn’t black turned into white, leaving only the line art. That’s where messing with the levels comes in.
Gimp, which is free, will do the same thing with colors, threshold. You may have to choose between leaving some of the darker colors as black or washing out some of the actual solid blacks, but I suspect it does the job nearly identical to Photoshop.
In either case you should convert the file to indexed color (1 bit) and save as tiff, bmp, or png and not jpeg which would reintroduce grays into the mix. You can save as a lossless compressed tiff for a very small file. And I’m pretty sure there must be a lossless png form as well.
You need to start out with an image that has black (or dark) outlines; otherwise you’re going to lose the boundaries. Once this is established, go into “Levels” and adjust the “input” levels. You’ll be moving the right-hand slider to the left, and you may have to play around with the center one as well. A lot depends on which original image you’re using.
desaturate it, adjust the curves until you get very high contrast and then use the threshold adjustment (all in photoshop > image > adjustments)
This. Most other approaches will either drop out too much or too little of the line art you want to preserve.
This can be done with just a few commands in Adobe Illustrator, using the Live Trace tool. It’s actually capable of converting many images into outlines.
The freeware version of Illustrator is called Inkscape, but I don’t know whether it has the same functionality as I haven’t used it much.
The OP doesn’t say he wants to edit the lines, just convert it to high-contrast B+W. Trace might be too complicated and fussy for that task, depending on how much detail and shading is in the illustration.
Raster tools for raster images; vector for vector.
You should also be able to select just the black in PS and delete everything else. Or alternately, use the selection tool and drop out one color at a time
I’ve had a lot of success using the live trace to create outlines of illustrations. Complicated pictures do involve a bit of deleting stray lines and playing with the trace settings, but on the whole it works pretty well.
So have I, but if the OP has to ask such a basic question and doesn’t mention what tools they have on hand, I’d rather steer them to a straightforward and simple tool than one using a tricky left-handed tool that can achieve the same result.
You could use inkscape to scan the image to vector format - and afterward, each colour would be a separate vector object - you can then delete all but the black lines - and the advantage is that the result is also smoothly scalable to any size.
Google “pen and ink”+“Photoshop”.
Converting to grayscale and increasing the contrast is the easiest way however if that doesn’t work you can use Replace Colour in Photoshop to select the individual colors and Transform their Lightness and Saturation to white.
Oh so now I finally understand what illustrator is all about, that it’s a vector graphics editing program! I never really looked much into it but I always wondered what it was for.