Vectorization of a raster image is important if you want to work on it using CAD tools. Vectorization is a term that is used to refer to the process of converting raster images to vector drawings. Before you understand the answer to how to convert raster to vector, you should first establish an understanding of what raster images are and how they are different from vector images.

Raster and Vector images
The raster image refers to an image that comprises of little squares arranged in the form of a grid. The arcs and lines drawn on this image are depicted by using various colors to shade the relevant pixels. These images are created when you take pictures on your digital camera, use programs like Adobe Photoshop to create any image or scan a drawing. Some of the extensions with which these images can be saved as are JPEG, TIFF, PNG, GIF, CALS, IMG and BMP.

On the other hand, a vector image refers to an image that comprises of well defined lines between two different co-ordinates. Adobe Illustrator and similar software generate vector images. Some of the common extensions used to save vector images are DGN, DWG, PDF, WMF, DXF and SVG. A notable difference between vector and raster images is that the former appears to have smooth lines when zoomed in as compared to the latter that appears to be jagged.

Why convert to vector?
If you plan to work on any CAD program, the first thing you need to do is to convert raster to vector. If you do not convert to vector, it will be impossible to work on the raster image that has been loaded onto the program. Though the raster image does get displayed, you will not be able to make any modifications to it. Any CNC or CAD program can only make modifications to vector images. Therefore, it is imperative to convert raster to vector to make the desired modifications. It is important to note that not all raster images can be converted into vector images. You have to first deskew the raster image, clean off the dirt and thicken the lines before scanning them. The software that can convert raster to vector has certain features that can rectify small broken lines and holes along the lines.

If you do not want to convert to vector, you will either have to redraw the raster image from the scratch using the CAD program or purchase redrawing software. The best option though is to opt for the services of an experienced CAD professional who can accurately convert raster to vector. Once the image has been converted to vector, you can easily import it into the CNC or CAD program and continue to work on it.