Isolating and Vectorising a scanned logo

Isolating and Vectorising a scanned logo

Introduction

Have you ever found yourself in the situation where you need to take a poor-quality scan of a logo and make it into something scaleable and clean? Sure, you could recreate the logo from the ground up, but that’s time-consuming and labour-intensive. What I’m going to present here is a technique you can use to tidy up a noisy logo and make it into a vector graphic using Adobe Illustrator, quickly and effectively.

This tutorial assumes you have Illustrator. Other vector graphics programs may differ, so we can’t guarantee it’ll work the same way.

The noisy original

You can see from this image the hurdles we’ll have to overcome. The image is horribly distorted, in this case from a noisy original and excessive JPEG compression. The colours are faded, and the edges are not particularly crisp.

Step 1: open in Illustrator

Create a new Illustrator document big enough to work with. For this tutorial I’m going to use a 15x10cm canvas in RGB mode (best for creating web graphics). Place the graphic on the canvas (File -> Place…).

Step 2: Live Trace

This is where the magic comes in. Live Trace is a tool Illustrator provides for converting raster (pixel) graphics into vector (object) graphics. When it comes to logos, vector graphics are far more useful because they can be scaled to any size with no loss of quality or precision.

With the image selected go to Object -> Live Trace -> Tracing Options.

There are several presets available from the Preset drop down menu, or you can fiddle with the settings yourself. I find it useful to tick the Preview check box, which will give you a live preview of the effect of the tracing options you’ve got selected. Another useful trick is to select “Outlines and Tracing” from the Vector drop down menu, which will show you what elements it is creating. Try a few of the presets to see your graphic being interpretted by Live Trace. The “Default” preset will probably have a good stab at finding the basic outline of the logo, but in our example it fails to distinguish between the orange and the yellow, so some tweaking is required.

Because the image is so noisy we are going to have to set the “Minimum Area” relatively high, so that Live Trace doesn’t try to create too many sub-objects for each area of noise. Putting the “Path Fitting” value up a bit may also help to smoothen out the edges. Below you will see the values I have used in this instance and the result previewed behind.

As you can see, Live Trace has found the edges of the objects and coloured them in for us. It’s not perfect, but it’s a good start and has saved us some time.

Step 3: Colouring

Select the Live Paint tool from the toolbox. When you click on the image you’ll probably be given a warning message saying that if you start painting it you won’t be able to go back and edit the Live Trace settings, but don’t worry about that. If everything does go wrong you can always undo.

The first thing we’re going to do is get rid of the grey background, so that we can place the logo on any background we like. To do this, select Transparent from the Swatches and click somewhere on the background. You will notice that when Live Painting the area you will be affecting will be highlighted, which is useful for telling what your painting.

We’ll also re-colour the logo itself to use bolder colours, as the original colours will have been washed out.

Refining the outlines

Now, you will notice that the outlines of the logo still aren’t completely fault-free. However, Illustrator will now let you edit the control points of that vector image to refine it further, if necessary.

Click Object -> Expand and click OK in the dialog box that appears. This will remove all the Live Trace elements and leave you with a simple vector object, as if you had created it yourself with the Pen tool, only without the hard work!

For the most part the Live Trace technique has worked, apart from a small area of noise near the bottom of the yellow overlap bit of the logo. Playing with the anchor handles will quickly iron that out (zoom in for more control).

This technique is really powerful and can save you a lot of time. This particular example could just as easily have been achieved by recreating it with the standard Illustrator tools, but for more complex shapes there is a definite advantage to using Live Trace. It may not be as precise as getting the original logo or recreating it from scratch, but if you don’t have those options available to you then this is a powerful technique to have under your belt.

This tutorial was written by Matthew Dawkins of Matthew Dawkins Church Web Design

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