How to Clean Up Scanned Line Art in Adobe Photoshop


(instrumental music) – [Instructor] Hello
and welcome to this DesignCuts video tutorial today. We’re looking at cleaning
up scanned line art. So I have a line
art drawing here that has been scanned
at a high resolution. I suggest that you always start
with a high-resolution scan and try and get it as clean
as you can in the scan itself, but this needs quite
a lot of cleaning up. One reason for this is
that I want this line art to be on a separate layer. So I want to be able
to, for example, put something behind it, so it needs to be extracted
from the paper background. It also needs quite
a bit of cleaning up. We’ll start by making
the background layer
a regular layer. In the most recent
versions of Photoshop, you just click on the lock icon. In earlier versions,
you need to double click the background layer just to
turn it into a regular layer. We’re going to extract
the white paper from this first of all. And to do this, we’re going
to use some magic want tool. It’s really the simplest
tool to use for this purpose. But the magic want tool has
two really important settings that are going to
be vital to us, and that’s the tolerance
and contiguous. Contiguous means that when you
click on the magic want tool, for example, if I
click in the half here, the selection of
pixels is limited to a group of pixels that are
all attached to each other. So you can see I can get
the ones inside the had, but nothing else. So we want to disable contiguous so that when we click
on some white paper, we’re gonna select all the
white paper in the document. And the tolerance
is important too. This varies between
zero and 255. And it says to Photoshop
when I click on a pixel, I want you to take some
additional pixels of colours similar to the
one I’m clicking on that are in the document. So the bigger the tolerance, the more pixels are
going to be selected. So for example if we chose 255 and if we click on the document, then the entire document has been selected
black, everything. So we obviously don’t want
the really high value, but we don’t want a
really low value either. Because if we select
the value of say one, I’m just gonna deselect
my selection here, and click on the document, then we’re only going
to get pixels that are pretty much the colour of
the one under the cursor and very, very close to it. You can see here we’ve
got lots of marching ants all over the place. So other pixels off colour
are not being selected, which are colours that we
really would want to get rid of. So, for a document like
this or an image like this, I would start at
something like 15. That’s a pretty good value for picking up the
variety in the paper, but not the black. So I’ll press Control
or Command + D to deselect the
selection I already have, and I’ll click once
in the document. And that selected
the white pixels. At this point if I’m
pretty happy with that, I’ll just press Delete, because I’ve got a layer
which is a regular layer. So if I press Delete,
the white pixels are going to disappear. And then Control or Command
D to deselect that selection. I’ll add a new white-filled
layer beneath this, so I don’t see the
transparency mesh. To do that, Control or Command, click on the new icon and
the layer appears immediately under the existing layer. White over here is
my background colour so I can press
Control + backspace, Command + Delete on the Mac, to fill that layer with white. If white were the
foreground colour, it will be Alt +
backspace, Option + Delete. So let’s see how good our
background removal was, and there’s a very
simple test for this. What we’ll do is select
our line art layer, and we’ll go to the FX icon
here and choose Stroke. And what we’ll do is make
sure we set a red colour or a colour that’s
really, really obvious. We’re going to make it
positioned in the centre. It’s really important
that it’s in the centre, not on the outside
or the inside. So make it in the centre and make it big enough
that you can see the dots in the document. And I’m gonna make mine just
a little bit bigger here. Okay, so I’ll click okay. So let’s see what we just did. We took a layer that has
some transparency on it. And we said to Photoshop, around the edges of
anything on this layer that has actual content,
whether it be black or grey, put a stroke. And so, all these little
dots are stray pixels. That’s really important
because if somebody, for example, bought this shape, and they went to put a
drop shadow on this clown, then each of these dots
would have a dot shadow applied to it. And so the document
wouldn’t be perhaps as they expected it to be. So this is what you do to
clean up your line art. We’ll go to the Eraser tool, and you want to select
a circular eraser. So let’s go ahead and
select a circle here, and it needs to
be 100% hardness. Do not put any softness
on this at all, because it’s an eraser. I’m just gonna cranks the size
up a little bit right now, but we’ll do it
later as we work. So let me just check and see if I can actually see my eraser. No, I can’t, so I’m gonna increase
its size a little bit. And what we’ll do is go over
the document with the eraser. And everywhere we
see a loose dot, we’ll put the eraser dead over
the top of it and click once. This is why you
have a hard eraser, because you want to
see where the brush is going to be erasing. So here if I consider
this to be a dot, I would be in big problems if I click the eraser right now, because I’m gonna be eating
into this other area over here. So I wanna make sure
that my brush is resized so that it goes over the
top of the dot there, but it doesn’t eat
into the artwork. So basically, you’ll
go around the document removing the dots by just
erasing over the top of them and then looking at
the dots on the inside and outside here. You can see that there’s going
to be a stray pixel in here. So I’ll just click
over the top of it. I’m removing the stray pixel, but I’m not destroying
any of the line artwork. Now, if you have a
lot of these dots, you might wanna go back and try your Magic Wand again, and just see if you can get
a better starting point, but you will expect
to find some dots, because the dots are
actually helping you. What you’re doing is you’re
not getting all the pixels. You’re just getting
most of the pixels with the Magic Wand tool, so you’re not eating into
the edges of your art work, because you wanna protect
some of this line work because that’s why you’re doing hand-drawn drawing in
the first place no doubt, is that they just
have a different
characteristic to them. So, be protective
of your line work and just assume that
you’re going to spend a few minutes
spotting these images. So I’m gonna go
ahead and do that and remove all these dots and I’ll come back
once I’ve done that and we’ll go onto the next step. So I’ve gone ahead and
spend a few minutes spotting this document. Exactly how many spots
you take is up to you. I certainly suggest that
you take out any spots that are loose around the
character or the drawing because they’re going to be
really embarrassing to have in the document. But how close you
come into the edges is a personal preference. Now I left a couple
of pieces here. One of them is this bit here, because there’s a simple
way of doing that. With the Eraser tool, you can
click once in the document and then Shift + click, and then the eraser,
like any other brush, will paint a straight line. And so you can remove
any edge detail very easily that way. I find using the open and
close square bracket keys as I work makes it very easy
to change the brush size on the fly. Now what I didn’t remove,
you might notice it in here, is any of the dots that
appear inside black areas because they’re not
straight pixels, they’re holes in the black. So there are areas at the black where I didn’t quite
colour it in exactly. And so we don’t want to
start removing those. Because if we start
removing those, they’re actually
just gonna grow. So, the more we
start removing them, you can see that his entire
nose is being eaten away here. So that’s not the
solution for those areas. So I’ve done that now. I’m gonna go back and
get the layers palette. I’m just pressing F7 to do that. At this point, we’ll
just remove the strokes. So grab the stroke and
drop it onto the trash can because you don’t
need it any longer. All it was doing was being a
reference point for lose pixels or stray pixels. So now you’ve extracted your
line work from the background. You can go ahead and
fix up these areas where there are pixels
missing if you want too, but you might find that
that’s actually the character that you want to give the piece. So that’s entirely up to you. If you want to get rid of them, I suggest you go to
the Eye Dropper tool and sample the
colour around here because it’s probably not black, but it’s probably
something dark. And then just go
and get a brush, a nice round brush, and let’s just work with
a hard round brush again and just spot these areas. So, don’t paint over them because you don’t
want to destroy any other texture around them, but you can see them
pretty obviously and you can just fix
the worst of them, or how the many of
them you want to do for your own
personal preference. You’re the artist. You just need to know how
to fix these things up to your needs. Now, if we haven’t look in here, let’s just go in close, you might see that there’s a
lot of colour noise in here. This has been scanned
not in black and white, but in colour. And so there are all
sorts of colours in here. If you don’t want that colour, if you just want it to be
black and white and grey, then you can choose,
Image, Adjustments, and then just go to Desaturate. This is not the best tool for
turning things into grayscale at any other time, but
it works perfectly here. So you just go to desaturate it, which will give you
black and grey pixels, instead of colour noise,
which is what I had there. It’s gonna depend though
on how you scanned it. Now again you can see
these lines are grey and there’s a lot
of texture in them. If you want them to be darker, here’s how you’re
going to do it. Grab the layer that
has the content on it and drag and drop it
onto the new icon, so you end up with two layers. Go to the top most layer and set the Blend
Mode to Multiply, and that will
darken up the lines. This is the before,
this is the after. And if that’s not enough, just drag this top most layer that already has the
multiply blend mode on it, and drop it onto
the new layer icon and you’ll get an
extra multiplier. At some point, you’re
not gonna get any change, but you can darken up the edges,
if you want to, doing that. Once you’ve done that, Control or Command + E
on the top most layer just merges these down. So, it would merge it all
down to a single layer. So we have line art and a separate background. This is now done to the
point where you could do a little bit of cloning perhaps if you needed
to fill in areas or if you were a
little bit disturbed at some area or how it looked. But assuming that
everything looks fine to you here right now, what you might encounter,
what’s often encountered is that your lines
aren’t heavy enough, and that’s a real problem because there is
on the face of it no really easy solution. So I’m gonna show you what I do when lines need to be thicken. I’ll target the line work layer and choose Filter, Other, Minimum. This is a filter
that is not here for the purpose of
thickening up lines, but it does a really
good job of it. You’ll want to set this to
roundness, not squareness. With squareness, you
get a lot less value on this Radius slider. So I usually choose roundness. And now you can set a radius. And as you do that,
your lines get thicker. So, let’s just click OK here, and then let’s do
a before and after. So this is the before and this is the after. Obviously, there’s a
whole lot of variety between those two points. It’s not sort of this or that, but you can thicken up line work should you wish to do
so using that filter. It’s Filter, Other, Minimum. Now you’re choosing Minimum, because what you’re
saying to Photoshop is I want the minimum line
weight to be this value. And if the lines aren’t
that value already, then they’re going
to be increased. The flip side is if you
want to thin your lines, you might get some value. I can’t promise that
it’s going to work, but you can try it with Filter, Other, Maximum. Here you’re saying I want
my maximum line weight to be this value, and you can bring your radial
down really, really small. I’ve got 0.2 here. And you may get some value
in thinning your lines. Try it. It often can save you from
having to redraw your artwork. I hope that you’ve
enjoyed learning these Photoshop techniques. Let us know what you think
in the comments below, and give us a thumbs up if you enjoy this tutorial. Until next time, I’m Helen
Bradley for DesignCuts.

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