Thursday, January 23, 2014

Restoring comics 101 - Adjusting colors (1)

It is time to address the colors of the scanned picture. This is mandatory for all old comics, often having faded colors and yellowed or browned paper. The ultimate goal would be to restore the art to the state it was a minute after it was printed. It is impossible to do this for many old comics, for reasons that we will explain, but we can do a pretty good job. Let’s see how.

There are many “philosophies” when it comes to retouch colors on old comics, and various “recipes”, from very simple and automatic to very involved and complicated. With time you learn to judge what is the best for your situation, depending on the goal you want to achieve.

Before continuing: it is always a good idea, instead of permanently modifying the pixels of our image, to use nondestructive modifications. In Photoshop this means using adjustment layers, so that if you change your mind you can always go back. In the following, for simplicity, I will work directly on the pixels. If you do so remember to save the unmodified picture and work on a copy.

Automatic quick&dirty

If the comic is not very old and it is not dirty or damaged the simplest thing to do (but by no means the best) is to use some automatic command from your favorite photo editing software.

In PS CS5 using Image>Auto Tone

Or Image>Auto Color

The other Auto command, Image>Auto Contrast, is not useful in this case since it will increase the contrast equally in all color channels (Red, Green and Blue) in the same way so that the colors will not be modified.

However, for serious work with old comics there are better way to keep the color adjustment under control.

Adjusting levels “by eye”

In Photoshop open the Levels command (Control-L or Image>Adjustments>Levels)

Note that both the black and the white of this panel are rather dark gray and light gray. In fact look at the histogram (the RGB channel): the luminosity levels go to zero well before going to the true black (0, to the far left of the histogram), or to the true white (255, to the far right of the histogram)

By the way: if you click the Options… button a new panel will appear showing the Auto commands we used above

Quick for the web

If we want to clean an image to be used on the web we usually want white to be pure white, (255,255,255) in RGB lingo, and black to be pure black (0,0,0)

For a quick fix you can use the black and white eyedroppers

Start with the black: grab the black eyedropper

and click in a place you believe should be pure black. You can click in different places until you are satisfied.

Now the black is “really black”. Repeat the procedure with the white eyedropper tool

and here the quick result

Remember that while you are inside the Levels command, by pressing the Alt key the Reset button will appear, and you can go back to your original image inside the Levels command and restart working from there.

Here is the final result

While adjusting the white it is tempting to use it to “whiten” dirty spots on the yellowed paper. Beware that by exaggerating you can end up with crappy colors like this

Even worse, if you work with old comics with very yellowed pages like this

you will end up with completely off colors

How to avoid this? next time :)

Dario Bressanini

No comments:

Post a Comment