What is raster to vector conversion?

What is raster to vector conversion (vectorization) and why do you need it?

If the following explanation sounds familiar, that's because it's based on my original explanation which I wrote back in 1995. The original has been copied many times - sometimes verbatim, sometimes edited, always uncredited - on other raster to vector conversion sites across the web!

A raster to vector converter converts a raster image to a vector image.

What is a raster image?


A raster image is an image made up of a grid of little squares called pixels. Lines and arcs are represented by coloring the appropriate pixels.

Raster images are created when you scan a drawing, take a photograph with a digital camera or create an image in a raster-based software program such as Adobe Photoshop.

Raster images can be saved as various sorts of file including BMP, CALS, GIF, IMG, JPEG, PCX, PDF, PNG and TIFF.

What is a vector image?

vector file

A vector image is an image made up of vectors - mathematically defined entities drawn between coordinates.

Vector images are created by CAD programs and other vector-based software programs such as Adobe Illustrator.

Vector image file types include DXF, DWG, DGN, HPGL, SVG, EMF, WMF and PDF (which can contain raster images, vector images or both).

Why convert raster images to vector images?

You will probably be able to load a raster image into your CAD program - most CAD programs can import and display raster images. However, once you have imported a raster image into your CAD program you will find that all you can do is look at it or trace over it. You will not be able to make any changes to it.

This is because CAD and CNC programs can only work with vectors. If you want to edit a raster image in your CAD program or cut it in your CNC program you must first convert it to a vector image.

To do this, you must either redraw the raster image manually using your CAD program or a dedicated redrawing program; get a manual redrawing service to redraw it for you; or use raster to vector conversion software. Raster to vector software attempts to convert the raster image to vector automatically.

Once you have converted the raster image to a vector image and saved it as a vector file you will be able to import it into your CAD or CNC program and edit it.