I recently received a call from a government agency looking for a cost to get their engineering documents in a digital format. Their first question they asked was “What will it cost to get my drawings scanned into AutoCAD?” At that moment, I knew they didn't really know what they were asking for. Unbeknownst to them, the cost to convert the drawings for this project would surely stimulate the economy!
I am no longer surprised by these questions. Not everyone understands the process in which you make your engineering data smart. It’s not just OCR, but more. First, let’s identify a few items. What do you really want to make intelligent? Maybe you only need a few items and not the entire drawing or maybe you need it all (text included). Know what you want.
Identifying what you want first is key in the conversion process. Converting a drawing to CAD is a multi step process. There is a scanning (300dpi or higher gets better results), Q/A, Corrections (deskewing, cropping, thickening and thinning the line work) and include despeckling. Cleaning up the image in the beginning will net you better results in the process.
Now, with the preliminary work done, you actually begin the conversion from raster to CAD. Conversion can either can be drawing manually using heads up digitizing (this is tracing lines like you did in elementary school) or you can utilize R2V software. This type software tool is like OCR but it’s more. It’s a tool that allows you different ways to interact with the data in the conversion process that makes it faster than heads up digitizing but with the accuracy you need. There are a few reliable products out there such as Autodesk Raster Design, GTX and WiseImage Pro. These types of software convert text to text, graphics to graphics and they place this data or the appropriate layer. NEVER do an automatic conversion.
To be effective with these software packages, you need to set up parameters for the software. This is where you define how you will drive down the “raster road” of line work. If you use orthogonal lines or if they are arc’s, the software follows these parameters.
The conversion process also includes enforcement of CAD standards. CAD Standards include line types, line colors, blocks (i.e. a desk or window and not a bunch of lines that look like a desk or window). Remember Standards in any environment are merely suggestions without enforcement.
Your data is an asset. Protect it in any form you have it. The more intelligence, the more value.