Scan2CAD v7.2: Raster-to-vector conversion

CADalyst, May, 2004 by David Byrnes

THOUGH MOST MODERN CAD programs display raster (usually scanned) images, you'll need to trace over or convert the raster image if you want to change it. Scan2CAD, now in its seventh major release, provides one of the most cost-effective tools for automatically converting scanned drawings to vector CAD files.

This is the third version of Scan2CAD that I've reviewed. V5 was effective, with its most outstanding feature being its low price. V6 kept the low price and improved in almost every way--in fact, it was one of the five-star, Highly Recommended programs in our last comparative review (July 2001, p. 30). This new version is a bit more expensive, but offers many new raster cleanup, editing, and conversion features.

Vectorizing a scanned drawing in Scan2CAD is a simple process. The program converts most common graphics formats, including BMP, PCX, TIF, GIF, JPG, IMG, and CALS GP4, CG4, CAL, and MIL image files. A first step is to run the Smooth tool to remove any stubble from the raster data so that there are nice clean lines for the vectorization process. Next, choose the type of drawing you're converting to set a number of conversion variables. Choices include architectural plans, contour maps, CNC profiles, even freehand sketches. If there is no text in your drawing, simply run the vectorization and save the results. Scan2CAD saves vectors as DXF (pre-Release 14 and Release 14 and later), HPGL, WMF, and EMF.

Drawings with text require one more step. Pick the largest text object in the drawing and optionally indicate whether run-together characters need to be split. Then select the Vectorize All button, and the software converts the raster data to vectors. No OCR (optical character recognition) software is perfect, but Scan2CAD does a reasonable job out of the box. The Pro version has font training so you can teach the software to recognize any font--even hand lettering.

Most applications in this category offer a similar range of abilities--raster cleanup tools such as despeckling and deskewing, and raster editing tools for scaling, merging, and deleting. What sets programs apart is their ability to vectorize, and Scan2CAD is a powerful contender here. As well as easy stuff such as lines and arcs, the program can recognize and convert Bezier curves, hatch patterns, and noncontinuous linetypes.

The program comes in two versions: Regular ($279) and Pro ($469). Both versions offer raster cleanup, raster editing, and automatic raster-to-vector conversion tools, including text recognition. The Pro version includes a dictionary to spell-check vectorized text, batch vectorization, color vector conversion, trainable optical character recognition, and a command-line interface. Scan2CAD is TWAIN compliant, so you can scan directly into the program. Its unique tiling feature lets you scan your drawings on a desktop scanner and then stitch the images together.

Documentation and support are first-rate. The user manual is available as an online Help file and as a 300-page spiral-bound user manual. This document is task-based, rather than a simple list of commands, and the online version includes six video tutorials on different aspects of the program. Program support is free and accessible by phone or e-mail.

Scan2CAD has most of the functionality found in programs costing up to ten times as much, and high on the list of features is its trainable text recognition. The newest version of Scan2CAD maintains the high standards of earlier releases.

SCAN2CAD V7.2

Raster-to-vector conversion

pros: Affordable, powerful, automatic raster-to-vector conversion; trainable

text recognition.

cons: None significant.

price: $469 Scan2CAD Pro; $279 Scan2CAD Regular

Softcover International Ltd.

606.564.5028, x229

postmaster@softcover.com www.softcover.com

David Byrnes teaches at British Columbia Institute of Technology and Emily Carr Institute of Art & Design in Vancouver, BC. He also coauthored and edited ten books on AutoCAD and AutoCAD LT and is a contributing editor of Cadalyst.