Adjusting
a Scanned Drawing:
An introduction to levels
Scanning
a drawing, sketch, portfolio piece, even a photo
is one of the black arts of photoshop. There
are people out there who know so much about
the adjustment tools that they can make any
scribble look amazing. I'm not one of those
people. However, this is the process I go through
when I'm scanning one of my drawings. Hopefully
you'll pick up a thing or two also.
Before
doing the tutorial: Scan your image. Some hints on scanning:
At a minimum, scan at at least 150 dpi.
I usually use 300 dpi myself, but for small
scans that I've needed to blow up to a larger
size I've had to scan as a high resolution as
600 or 1200 dpi. Be careful scanning little
bitty things at high resolutions though, most
scanners CAN'T scan at the top resolution
their box says they can. They scan as high as
they can and then interpolate (guestimate)
the extra pixels. I usually do not scan in black
and white, even if the picture is in black and
white, since I like the ability to adjust the
temperature of the pic myself. (but that's for
another tutorial)
Right
away crop and orient your image. It's good to
crop before you mess around with remastering
the image so that the only factors involved
in the adjustments are from what the final image
will be. You won't have a glowing white border
from the scanner lid screwing up your levels
this way.
Ok,
this Robot gal I drew (it's only an hour of
work, so be kind) lends itself well to this
tutorial, with a variety of headaches to deal
with. Right away you can how washed out the
scan looks. There's also those little gesture
sketch lines behind her to deal with and a couple
of other blemishes.
YOU
COULD DO IT THIS WAY....
The sketch lines and the washed out look can
be dealt with at the same time with the power
of levels. Instinct might make you tempted to
use auto levels simply because it's quick and
painless, and as you can see below, autolevels
(found under image>adjust) will make the
image pop out, but it doesn't get rid of those
gray sketch lines.
BUT
THIS WAY IMPRESSES MORE GIRLS:
Here's one of the ultimate Levels tricks. Open
up adjust levels. See the fancy black bars and
buttons? Ignore them. They basically tell you
how much of the picture is white and how much
is black, and you can alter that if you want
to by sliding the triangles, but the easiest
way to do what we want here is to just pay attention
on the little 3 eyedroppers that appear below
the "ok, cancel, auto, buttons". Choose
the one that is filled with black, the first
one. By clicking on the darkest part of whatever
image, you reset the black point to make that
spot pure black, even if it's not.
Sidenote:
You don't have to permanently apply levels or
any adjustment to an image. Starting with Photoshop
6 there has been a little thing called adjustment
layers. They're update-able adjustment effects
that you can apply or remove just like any other
layer. (click the little half circle on the
bottom of the layers palette to apply one)
If
you guessed that the far right dropper, the
white one, is used to set the whitest point
your right, but that's not what we want to do.
If we set the whitest part of the document as
white, then we'd end up doing the same thing
that "autolevels does". Instead I
use the white dropper to click on the gray I
want to get rid of. It'll turn everything that
tone or lighter to a pure white, eliminating
all our sketchiness problems!
The
result of setting
White/Black points
It's
not flawless, a few spots that are only visible
up close still present problems, but most of
the work is done.
To
get rid of these without messing up the rest
of the picture, select them loosely.Feather
the selection, (select>feather) the number
of pixels depends on the resolution, but between
5 or 10 is good.
This
blends any work we do to this area into the
rest of the picture, eliminating the hard line
of the selection once any correction has been
applied.
I
used levels again here. You could use the
exact same procedure as before just at a closer
detail, but for the sake of being different,
try something else. By dragging the white
triangle on the slider toward the black triangle,
the smudges and grays will fade away. Don't
drag too much, or the selection will end up
too different from the rest of the image.
You
could have done the first adjustment this way
too, but tweaking the sliders correctly at that
point would have been more time consuming. You
can also use the sliders at the very bottom
to limit the range of colors.
Here's
the finished scanned and fixed up image. Since
(if you scanned the image like a good little
graphics junkie), it's at a higher resolution,
you can output it to your printer, to the web,
or for use in other projects. I also used the
eraser and clone tool to clean up the image
a little bit, but that's for another tutorial.
If
you find any errors in this tutorial, I'm
not perfect. Send me an email
and we'll figure it out.
