Illustrator Image Trace

Adobe Illustrator's Image Trace function is a quick and easy method of converting a bitmap image into a vector image, and useful when cleaning up low resolution images or logos. This function was known as Auto Trace and Live Trace in previous versions of Illustrator. However, the options have not changed much at all since version CS2.

Create a new document to begin with. Go to the File menu and choose Place to import a bitmap image, usually a JPEG. This may be a photograph or an image which has been scanned. It's actually easier to work with low-resolution images since Illustrator does the conversion calculations much faster than with higher resolution images. Sometimes, if the original image is of a large resolution, the message appears saying that it could take some time for Illustrator to calculate the vector conversion. This is not usually a problem - only a matter of seconds. However, the problem is more that when expanding the image, we have to deal with lots of very small vector shapes. In the end it's easier to open the image in Adobe Photoshop and down-sample it to a screen resolution of 72 pixels per inch.

When the image has been placed, the Image Trace options will appear at the top Control panel. Click this icon and the image will be converted automatically to a plain black and white vector image. We usually want to modify this basic conversion. The Image Trace panel also opens on the screen, with various tracing Presets and options.

First choose a Preset from the drop-down list. To begin with, choose one of the presets which best matches your original image, eg. a photograph, or a scanned drawing. This result can be adjusted further.

Colour options are also available via the Live Paint function, the icon for which appears on the top Control panel also. The paint may leak through gaps in the artwork, in which case we use the Gap Options settings. Tick the Gap Detection check box and Choose Paint Stops at: Medium Gaps, for example. Then hit OK.

Other colouring options are available by expanding the image via the Expand button on the Control panel. This breaks the image up into smaller pieces like a jog-saw. We can then use either the Direct Selection tool (the white arrow) or the Magic Wand tool to select and change areas of similar fill colour. It's also possible to use the Knife tool to break up areas of colour into smaller parts. The Eraser tool may be used to erase large chunks of unwanted colour. In this way we can pare down and simplify our design.

Like all vector images, the design can now be scaled without any loss of resolution. Vector images are known as "resolution-independent", meaning that we can scale them up or down without loss of detail. This is due to their mathematically created nature. When we scale upwards, the paths which comprise the design are recalculated. Vector images are also small in file size, again due to their mathematical nature, as opposed to bitmap, pixel-based images which contain colour and brightness data for each pixel.


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Tom Gillan has been training Indesign to corporate clients in Sydney for seven years. You can learn more about Adobe Illustrator Courses at http://www.designworkshopsydney.com.au/adobe-illustrator-courses/ .