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In this exercise, we're going to take a look at the larger world of tracing
options inside the Tracing Options dialog box and boy oh boy are there a lot of
them, but they're actually pretty easily digestible. They all make a fair amount of sense once
you come to terms with them. So I've gone ahead and saved my progress as
Threshold 240 MA 5px.ai, very friendly name of course.
But the idea is we've applied a Threshold value of 240 and a Minimum Area value
of 5 pixels, hence the name. Anyway, I've got my object selected, my Tracing
object right here. I would like you to make sure yours is selected
as well. And then go up to this option, the Tracing
Options dialog icon and click on it to bring up the Tracing Options dialog box.
Now notice what we have here is the series of Adjustments options and then the
series of Trace Settings options. Below them we have these Preview options and
the Raster options match exactly those that are available to us from the chunky
pyramid and the Vector options match exactly those that are available to
us from the smooth pyramid. So these are exactly the same options, so
we can control what we're seeing in the way of the Vector results and what we're
seeing in the way of the underlying Raster image, the pixel-based image.
When the Preview checkbox is turned on, so I recommend you to go ahead and turn
that Preview checkbox on, so that we can keep track of what we are doing.
Not coincidently, these Adjustments options right here affect the Raster
image, the pixel-based image and these Trace Setting options right here affect
the vector results. So it makes a lot of sense that these options
are all organized together over here on the right side of the dialog box and
these options are organized together on the left- hand side of the dialog
box. We're going to take a look at the Raster options
inside of this left area in this exercise and then we'll take a look at
the Tracing Settings options, the Vector options over here on the right
side of the dialog box in the next exercise. All right, we start off with the Mode option
and Mode determines the Color mode. So are we going to trace colors inside of
the image, are we going to trace Gray values or are we going to just trace Black
and White? And of course, in the case of this image right
here, we just want Black and White. There are no colors to work with, so we certainly
don't need color. If we added Grayscale, we just trace a little
bit of gray along the edges and that's not going to do us any good.
In fact, it looks ratty. So for this particular image we definitely
want black and white. Now, where we need to switch to one of the
other options, such as Grayscale for example, then we would lose our Threshold
value right there. It would become dimmed.
So Threshold is specifically applicable to Black and White.
Whereas, these other dimmed options right here, Palette and Max Colors, they are
only available to us, if we're using something other than Black and White, such
as Grayscale or Color. And we'll see those options later on when
we take a look at color tracing inside Illustrator.
But I'll tell you that the Palette setting effects which color palette gets
used, so which specific colors are used to trace the illustration.
And Max Colors effects how many colors maximum are going to get traced.
Then if we do go ahead and trace colors, we can Output them to Swatches, here
inside the Swatches palette. That's not going to do us any good for black
and white, because we're going to either output black or white and that's it.
So we've already got black or white in the Swatches palette, we don't need that.
Next, I'm going to skip down to Resample right here.
The Resample option allows us to reduce the number of pixels inside of the image
or enhance the number of pixels, add pixels to the image if we wanted to.
That will be really useful if we had a high-resolution image that was captured
by a digital camera or a scanner and we need to reduce the number of pixels in
the image, in order to increase Illustrator's performance.
Because if you have 300 pixels per inch to work with, you're going to get very
sluggish results and you are not necessarily going to get better results either.
What I prefer to do, however, is define the image at a low resolution inside
Photoshop, before bringing the image into Illustrator in the first place.
So we only have 72 pixels per inch to work with, we don't need to change
this Resample value. Blur is another thing entirely.
Blur can pretty much completely upset the apple cart.
Let me show you how it works here. I'm going to go ahead and change the Blur
value. Let's say to 4 pixels and then I'll press
Tab and we'll see the letters expanded like crazy here.
Now, if you want to get a sense of what the Blur really looks like, let's go
ahead and switch the Mode from Black and White to Grayscale and then we'll see a
bunch of different colors going on here, as you can see here, bunch of Gray
values and for a moment let's turn off Tracing Results.
So we can see the Adjusted Image without assigning a bunch of vectors to it,
which will flow things down. So set Vector to No Tracing Result.
Then its looks really chunky, not blurry at all, like really jagged actually for
a blur result and that's because we only have six maximum colors.
If we went ahead and crank that up to 256 and press Tab, you would get some
fairly soft results in the background of course at a low resolution, because
we're just working at 72 pixels per inch. But anyway, that's what the Blur really looks
like, but then when you convert it to Black and White then the Threshold value
comes into play. So because we have a high Threshold value,
we're taking a lot of that Blur and converting it to black and just a little
bit of the blur and converting it to white. So we're growing the letters outward as we
blur them. Were we do reduce that Threshold value, I'll
take it down to 20 and press the Tab key, then you're going to reduce the size
of the letter. You're going to make them thinner and some
of the letters are going to almost completely blur away.
Blur isn't useful to us where this illustration is concerned. Not at all.
In fact, it's only useful if you have a lot of artifacts inside your image.
A lot of dust, a lot of scratches, a lot of particles, all that jazz.
If it's a scanned image with a lot of junk in it, that you want to blur away,
then Blur becomes useful. Otherwise, though if you have the noiseless
image like this one here, and generally speaking I have to say, You might
as well make the image look even in Photoshop before you take it over here, into
Illustrator, because otherwise you are kind of wasting your time a little bit
and I'm going to go ahead and take this value down to 0, which is what I recommend
on a regular basis. So I'm going to take the Threshold value back
up to 240 by the way and you'll notice that really we haven't made any changes.
I don't want to make any changes here inside the Adjustments options.
I'm going to change the Vector Option back to Tracing Result, down here in the
Preview so that we see the trace letters. In the next exercise, we're going to take
a look at the more useful, at least to us, Trace Settings that directly affect the vector
based results.