Join Deke McClelland for an in-depth discussion in this video Tracing options: The raster functions, part of Illustrator CS5 One-on-One: Advanced.
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In this exercise, we are going to begin the tour of the settings that are available to you inside the Tracing Options dialog box. Those settings are divided into two groups. First, you've got the Raster settings, which determine how Illustrator converts the pixel-based artwork before tracing it. Then you have the Vector settings, which determine how Illustrator generates the vector-based path outlines. So we are going to start with the Raster settings inside this exercise, then move on to the others in subsequent exercises. I have saved my progress as Black white & yellow.ai, found inside the 13_live_trace folder.
I will go ahead and select that Live Trace object by marqueeing around it with the Black Arrow tool, and then in order to further modify this artwork, in order to customize my Live Trace settings, I'll click on this little dialog box icon available to me in the Control panel, which brings up the Tracing Options dialog box. Now notice here at the bottom of the dialog box that we have these preview options, they are divided into the Raster preview settings, which are the exact same settings that are available to us from this jagged pyramid up here in the Control panel, and then we've got the Vector settings, which are those settings that are available from the smooth pyramid.
Now not only are the preview settings divided into Raster and Vector down here at the bottom of the dialog box, but they're divided in exactly the same way, that is, the settings throughout the dialog box are divided into Raster over here on the left inside and Vector over here on the right-hand side. So every one of these left side adjustments effect how the image is converted before tracing it. So right now the image is left in color, we could convert it to Black and White if we wanted to, which would wake up the Threshold option and make dim the palette and Max Colors options.
However, I am going to leave the image set to Color for now. You can change the number of colors using this Max Colors option, which works exactly the same as it does in the Control panel. I am going to skip Palette for now, because if you were to click on Palette, you are only going to see Automatic, you are not going to see Twelve plus B&W yet. We are going to come to that in a moment. You'll only see Automatic until you load another Swatches palette and I'll show you how that works in just a moment. But for now, we'll skip this option. You can Output to Swatches by the way, after you get done Tracing however many colors you decide to work with, then you can output those colors as swatches inside the Swatches panel.
You also have the option - I am going to drop down here - of changing the number of pixels inside the image. So I could go ahead and actually increase the number of pixels if I want to, and let's say I decide to change this value to 200 pixels, and then press the Tab key. I can either click the Preview check box in order to see what's going to happen in advance or I could just click Trace, I could just decide in advance that I am going to trace my artwork, because what I want to do is I want to not only trace the artwork, but I also want to go ahead and zoom in.
Now that's going to cause Illustrator to do this on this particular machine. It's not only showing me a Progress bar, but for a moment it's showing me that it is not responding. If you have that problem, just go ahead and click inside of Illustrator, seems to take care of the problem, and the program gets back in business. Anyway, I am going to go ahead and zoom in on my artwork here, kind of down in the lower portion, and notice that increasing the resolution of my artwork in advance of the image has not done me any good whatsoever. It's in fact, it's made my letters much more jagged, and that's because essentially what I am telling Illustrator is to trace each and every pixel in detail, instead of applying any of its smoothing algorithms and that's not what I want at all.
So up sampling your image is a very bad idea when you're tracing. You may want to down sample, but that's it. In other words, you may want to reduce that resolution value, you will not want to increase it. Anyway, I am going to go back up here to my Tracing Options icon, click on it, and I'll change that Resample value to 72, and to see the difference, this time I will turn on the Preview check box, and notice that all of my letters go ahead and smooth out quite dramatically. They also have this Blur value, it is set to 0.2, because I start things off using that Comic Art preset.
What Blur is doing is it's blurring the original image in order to smooth over any defects. Once again, if you have dust and scratches from your scanned artwork, why then, you can blur some of those dust and scratches away. I consider that to be a very sloppy solution. You're much better off cleaning up the artwork in Photoshop in advance. If you apply much of a Blur value, for example, I'll take this buy you up to 4 and press the Tab key, then you are going to round off these letters like crazy. They are going to get extremely gummy indeed, and that goes for all of your other artwork as well.
I would never, ever, ever take this Blur value beyond 0, leave it set to 0 and you're going to get the best results. All right, there is one option outstanding, over here on the left-hand side, and that's palette. Let me show you how that works. I am going to go ahead and click the Trace button in order to apply my settings so far. Now you may recall, when we bumped up the number of colors, we got all kinds of weird colors inside of our traced artwork. For example, if I take this Max Colors value up to let's say 14, which is the number of colors I really need, that's how many colors are used in the original image.
So I'll go ahead and apply that value and then we get all these Progress bars and all these weird colors with all these sort of additional edges going on that I don't want. For example, around this 9, we have got a couple of different edges. Well, if you really want to isolate exactly the colors that you used, it's a lot of work, but what you can do is you can turn off your Tracing results, you can switch to Outlines or No Tracing result whatever, and then bring back your original image, which I already have displayed, so that's good.
And then you would switch to the Eyedropper tool, and you would click inside of one of these characters in order to lift its exact color, and that would nail that color here inside the Color panel. Then you would switch over to the Swatches panel, you would add a new swatch for that color and so on, and add one swatch after another. As I say, it's a big pain in the neck, and then you have to save those swatches out as an independent Swatch palette, which you do by go into this little Folder icon right there in the bottom-left corner of the Swatches panel and then you choose this very first command, Save Swatches.
What I want you to do is instead of going through all those steps, might as well just load the swatches I've created for you, and it's a file called Twelve plus BW, you'll go ahead and select the Other Library command by the way. Navigate into the 13_live_trace folder, and then open this file, Twelve plus B&W.ai. I am going to go ahead and just select this option, because I have opened the file in advance and that gives me this palette of swatches right here. Now then, I can switch back to Tracing Result, so I can see my tracing.
I can click on this little Tracing Options dialog icon and I can say, okay, I want to go ahead and use that Twelve plus B&W palette, and that is 12 colors plus black-and-white for a total of 14. Max Colors is now going to be set to 14, and it's going to be dimmed, because that's the number of swatches that are available inside this palette. If I turn on the Preview check box, I may or may not see some kind of change happen in the background, in fact, I do actually, and it's a good change. So I have given the 9 a better color.
That isn't to say, I am necessarily not to going to have any intermediate paths, I may, but at least I will go ahead and assign the proper colors to the proper path, and now I'll click on the Trace button, in order to apply those settings for real, and let's go ahead and zoom out from the artwork and see what we have come up with. Now it's very important that I not only nailed every single color inside of this image using that Eyedropper and adding swatches to the Swatches panel, and the whole number, but it was also very important that I added a swatch for black and for white.
You have to have those two swatches in order to make this technique work. Now I am not suggesting you are going to do it very often, but those are the various Raster settings that are available inside the Tracing Options dialog box. In the next exercise, I will begin to show you the Vector settings.
- Tracing a pixel-based image
- Sketching and drawing for Illustrator
- Creating and editing gradients
- Creating multi-colored blends
- Creating seamlessly repeating tile patterns
- Creating interlocking artwork with Live Paint
- Designing advanced type effects
- Recoloring artwork with color harmonies
- Making the most of symbols
- Integrating Illustrator with Photoshop
- Using transparency, blend modes, and opacity masks