Well, I've been working for a while now at trying to colorize things. Most of them stink enough to keep themselves off the site. Some examples include:

All of them had the same problem, after autocorrecting the image, it was impossible to use a threshold on them. This leads to the gray at the bottom of the colorized Josephine (Far left), or 3 hours of line removal as was used in the Nikita. Considering that what you see here is what I was actually editing on those two, that means that I was actually going pixel by pixel with Nikita. The Jim image was made from the composite image. All of them took an extraordinarily large amount of time. This is unacceptable on my tight work/school/FFXI/server maintenance schedule. So I needed a better way of making solid line drawings that I could use a threshold methods on without having too much noise to reasonably remove. This is where the blue line method comes in.

To begin you will need 3 things:

1. Clean plain white paper. Dirt, smudges, etc are very undesirable.
2. A black source. I use a .5 mm or .7 mm mechanical pencil. However, wood pencils, felt tip pens, etc. can be used. Just make sure that the pen is felt tip, otherwise the depression that the pen leave will contaminate the image.
3. A light blue source. I use some Pentel brand blue .7 mm lead in a cheepo BIC mechanical pencil. This leaves a faint, but visible blue line. The closer to computer blue (#0000XX, where xx is the brightness), the better.

Once you have these things you are ready to go. Start off by drawing your draft picture. Remember that if you need guide lines, etc. you can draw them safely with the blue pencil. They will be removed later in the process.  Don't draw to dark though, it may cause depressions in the paper, or dark spots that will have to be removed manually later. The blue lead that I use is uneraseable with the stock erasers in my pencil, so keep that in mind while you draw. When you are done, you should have a faint picture. It will have lots of lines that mean nothing, or where a path you wanted to follow, but decided against. This is ok.

Now, for the next step, find a table that you are sure is going to be bump free. Now, carefully draw a single, dark line following the image described with your blue source. This will make up your final image, so you want it to look good. If you're using ink, triple check that the line you are about to ink is really the line that you want to show up. You don't want any guide lines ending up in your final drawing now do you?

When you're done you should have an image like this:

Notice that guide lines and the whole lot are still in there. This is okay. The next step is the one that makes the extra effort all worth it. Now, if you don't have my special software (which is availible for download at the bottom of this page), you can cheat with the right graphics package. All that needs to happen (and all that my software does) is you need to split out the blue channel of the image. This way white and blue are the same color. Most packages split the image out as a grayscale, so all you need to do is convert it back into a true color drawing and PRESTO! You have an image sans the blue lines. The image aboce, after blue line removal, looks like this:

(Heh... Forgot to blacken a line when I drew the TV, check the original and you can see the unblackened blue line.)

Now, both of the images above have been adjusted for visibility in the guide, but DON'T DO THIS! The reason should be clear from the above image. Notice that the mild smudges on the paper show up? This will give you massive headaches in the next step. If your image is faint, don't worry about it.

The next step is the threshold adjustment. Most good drawing packages have an adjustable threshold tool. What this tool does is take anything over some limit (The Threshold) and make it black. Everything else is make white. This allows you use the wand tool (or whatever it's called in your paint program) to select all of the white area and fill it. Applying the threshold properly takes some experimentation. Try a couple of different thresholds. If your threshold is too high, there will be a lot of gaps in your lines, which all have to be filled. If your threshold is too low, your image will have a lot of noise (dots that aren't really part of the image where a speck of dust darkened the image enough to exceed the threshold.) When the threshold is done, it looks like this:

In any case, you will then need to do a pass on all of the segments to make sure they are closed. Every place you plan to put color will need to be closed so you can fill it properly. This means using the wand tool on every color zone and checking to make sure it doesn't bleed (select things outside of the color zone.) Then you need to clean up any noise that has been added to the image, unless you want to leave it in for some artistic reason beyond my comprehension.

The final stage is colorization. This process is completely up to you. I don't have any set methods I use to colorize, so I can't tell you how I do it. :) It just means you're going to have to experiment on your own. But when you finish you'll have an awesome colorized drawing like this:

And there you have it. If you have any comment or suggestions, feel free to write to me @ jtc@nqig.net.

Have fun! And good luck!

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