WinTopo

Vectorization sounds complex, but in fact it's the fairly simple process of converting raster images, which we'll call "pictures," into vector sets that can be used in CAD, GIS, CNC, and similar digital design, control, and automation environments. Simple, yes; but elaborate in methods and processes. That's where WinTopo Standard enters the picture. It's a free tool for extracting vectors from JPEG, GIF, PNG, and other images. It's essentially a pared-down version of a pro tool, but its results are more than good enough for millions of users, apparently.

WinTopo's interface resembles the bulk of graphics and design tools out there, which is just fine since the basic file menu/toolbar/main window layout is hard to beat for efficiency. WinTopo Standard offers fewer features than the pro version, yet shares the same toolbar, so some buttons are inactive, such as the Best Combination thinning tool and Simple Edge Detection tool. WinTopo uses a two-stage process to extract vectors: thinning, which reduces the image elements to pixel lines, and extraction of real vectors from the lines; the freeware uses Stentiford and Zhang Suen thinning and Canny edge detection. You can also draw, crop, erase, and perform other simple image-editing tasks from the toolbar. We clicked on the button to set the options for single-click vectorization and opened an image. The One-Click button quickly processed the image, displaying vector lines in green over the original. We were able to save both the vectors and the image in a variety of formats, everything from machine-readable files to PDFs and JPEGs. Next we opened another image and tried thinning and extracting the image manually, with similar results. The Undo command doesn't seem to function in the freeware, which would seem to be an unwise omission since the freeware users are the ones who are likely to need it the most. Nevertheless, WinTopo proved plenty easy to use. We especially like its capability to directly acquire TWAIN images from a scanner or other source.

For people who don't want to spend big bucks just to digitize images for their geographical software or CNC lathe once in a while, WinTopo is just the thing. It's more than competent for many other applications, though.