@ Adam
My way of getting clean lineart/sketches. Which may or may not be the most optimal way of doing things, but it works for me:
Firstly, you'd need to get a much better image of that scan than what you've taken. Right now it's rather obvious that the area on the left side of the image is somewhat darker than the right, and you can see the table at the top of the image, and there's an obvious colour cast (I'm guessing you photographed this under incandescent light), which may cause noise issues.
You'll need to get it as evenly illuminated as possible, otherwise you'll get an image that has patches of gray which will be hard to remove unless you're willing to spend time hand-painting it away.
Ideally, you should get this scanned using a scanner. Otherwise, you need to get a really clean photograph with no shadows. Suggest reading these to get the optimal image:
http://emptyeasel.com/2007/01/19/how-to-ph...r-the-internet/ and
http://emptyeasel.com/2009/09/17/camera-ti...rk-for-the-web/Once you get your clean photo/scan, it's ready for processing in Photoshop. This is what I'd do in Photoshop CS5:
(Steps 1 and 2 are actually optional, but I use them if the image has a colour cast, so I can get a clean grayscale sketch)
1) Layers -> New Adjustment Layer -> Channel Mixer.
2) Select option of channel mixing that produces the cleanest image, i.e. the least noise. There are various preset "B&W with X filter" options, you'd have to test for yourself to see which preset produces the cleanest grayscale image.
3) Layers -> New Adjustment Layer -> Levels
4) Push the white slider towards the left to get pure whites. You will probably have push the gray and/or black slider towards the right to compensate for "blowout" or loss of colour.
A more obvious tutorial (with helpful images) can be found here:
http://www.jmort.com/tutorials/scanning.html#levelsThis post has been edited by DragonReine: Feb 6 2012, 07:19 AM