BSA Committee on Design Software
16. Paper to CADD software and Services ( Scanning / CAD Overlay ) Raster to Vector
Note : There are several different technologies in this category. Essentially the issue is getting from raster (dots) used by digital cameras, scanners, and imaging software to vector (lines) used by CADD software. Many CADD programs allow you to take a previously scanned image and pull it up as a background to trace. (CAD Overlay, AutoCAD 2000, ArchiCAD, DataCAD Plus, VectorWorks) There are also programs which will "autotrace" what it thinks are lines, though all the results of such programs usually ends up in one color on one layer needing a huge amount of cleanup (so while they may work for certain things like solid contour lines they are terrible for getting architectural floorplans into CADD). Neither of these techniques is recommended, as re-drawing the files into CADD (and checking every dimension) is preferred. (Streamline, Corel Autotrace, scan2cad) However, since the CAD Overlay approach does involve re-drawing the project, just giving the background image as a reference, it is slightly better.
If the building is existing, also check the section on Photogrametrics and Site Surveying.
CAD Overlay type software CAD Overlay, AutoCAD 2000, ArchiCAD, DataCAD Plus, VectorWorks |
CAD Overlay type software
CAD Overlay, AutoCAD 2000, ArchiCAD, DataCAD Plus, VectorWorks
CAD Overlay - the standard in the industry, used by virtually all of the "vectorizing" services - they also offer CAD OverlayESP which adds the ability to work with the raster images (kind of like PhotoShop) and erase portions of the scan and combine it with vector CADD lines
AutoCAD 2000i = http://www.autodesk.com - in 1997 Autodesk bought the company that makes CADoverlay and incorporated part of those abilities into AutoCAD 14 and even more abilities into AutoCAD 2000i
ArchiCAD = http://www.graphisoft.com - very easy image insertion and scaling
DataCAD Plus = http://www.datacad.com - DataCAD Plus but not DataCAD 9 allows background images for CADD overlay drafting
VectorWorks = http://www.vectorworksarchitect.com
Cinema 4D = http://www.maxon.de/
Autotrace type software Adobe Streamline, Corel Autotrace, scan2cad |
Adobe Streamline = http://www.adobe.com - perfect for logos, this software c. $300 will easily and automatically trace drawings you have scanned in
Corel Autotrace
scan2cad - simple commandline shareware - creates a DXF file with tens of thousands of little short lines, allowing you to then import it into any CADD program and trace it there.
Paper to CADD Services (usually themselves use a CAD Overlay type software done by humans at low drafting payscales)
User Comments :
Date: Mon, 25 Dec 2000
Subject: Cinema 4D
do You know Cinema 4D? Perhaps a good addition to your summary http://www.maxon.de/ The data exchange to Allplan V16 it´s phenomenal, gigantic, incredibile, friendly greats Holger
Date: Fri, 11 Aug 2000
From: Leslie Javorek <eji@BBS2.RMRC.NET>
Subject: Re: OFF: Paper to Cad Services
Andrew M. Fethes, RA, NCARB inquired:
> Does anyone have any experience with services that claim to convert paper drawings to Cad files? I am about to begin a large restoration/renovation project on a circa 1920 brick building with a significant amount of decrative ornamentation. I am not too keen on drawing this all myself, and resonably clean "blueprints" exist and could be used for conversion.
Andrew -
If by "paper to CAD" services you are referring to a software solution that can take a scan drawing and convert it perfectly into an elegant and correctly scaled vector image that requires no further editing or manipulation, the answer is it doesn't yet exist under any publisher or on any platform. At the same time, I've been able to elicite some quite acceptable and useful results using Adobe Streamline (less than $300 retail) on a 300 dpi scan which I then import into VW as a .dwg file. The quality of the results depend upon the quality and total size of your original, how much tweaking time you spend in Streamline setting up your scan conversion, and how you intend to use the final result (i.e. does it matter if the molding profile you plot out is made up of 1000 lines that are less than .001 mm in length versus a single polyline made up of numerous complex bezier curves as long as the difference is invisible to the naked eye on the final plot?)
On the other hand, if you're asking about one of the companies or individuals who advertise that they provide "paper to CAD" services, wherein you submit your hard copies to them and they in turn generate an CAD file containing this info, then there are a number of factors you should consider and ask- Such as:
1. Clearly define (in writing) what your end use of the file will be for in terms that clarify the degree of accuracy in scale (including line thickness, dimensional tolerances, editable text, ability to create useful 3d extrusions, size limitation on the file itself, class and layer assignments, individual items versus groups versus symbols, attached records, etc.) You will find many providers able to provide you with the first few of those options but very few able to provide all of them. Be forewarned though that if you do NOT specify any of these (or other) variables, you should expect to receive back nothing better than a standard scan that has been converted to a vector file WITHOUT special tweaking - which means at best it will look like a fairly reasonable concept sketch but not something you'd want someone to scale off of or depend upon solely to build from.
2. The majority of providers publicizing such services through high-visibility web-sites, blueprinters or other such shops are actually simply the middlemen for draftsman and engineers (students and/or professionals) in countries such as India where wages are low even for those with excellent technical skills. This may or may not cause a problem depending upon the particulars of your project, how good you can communicate your needs to the middleman and how well he relates those to the company he's contracting with and how pure that info is translated to the draftsman. While most of these companies and individuals speak English better than most Americans, there are still cultural differences and standards that can often affect interpretation of your instructions and expectations and of what's on the printed page submitted. Turnover on your work with these companies is generally no worse than 100% "local" provider and actually often quite better. If you are satisfied with the results from one such provider though you need to keep in mind that this may not necessarily reflect the quality of the results you can expect from them forever after. (No way (generally) to guarantee same draftsman will be assigned to your next task.)
3. Cost is a fairly good gage as to the degree of detail, accuracy and editability you can expect to get back - but there are always exceptions on both ends of the scale. Again, always make sure you're comparing apples to apples (I'll let the others on the list rag on that one...<g>
Just to be fair, honest, above-board and Oh, Yeah, a little self-promotion here, I should disclose that I run one of those "local" companies and am one of those individuals who offers "CAD to Paper" (amongst other Services) and if you'd like more specific info, just e-mail me directly (eji@bbs2.rmrc.net) and I'll get back to you by e-mail, phone or fax (whichever you prefer). Leslie, Leslie Sigal Javorek,President, ELLIS JAY Inc. eji@bbs2.rmrc.net Cleveland, Ohio USA