A big portion of the userbase for most CAD software are architects, designers, and engineers. For most of these users, CAD software is extensively used to draft up floor plans and technical drawings. In a lot of these cases, these drawings will have signatures or professional seals to comply with title block regulations or standards.
Drafts might resort to taking scanned copies of the signature and then import these into the drawings. Now, this poses a lot of issues, including the pixelated looks of most scanned images inserted into CAD drawings and the usability of CAD files that contain inserted raster images. The better but more tedious option would be to trace these signatures to create vectorized linework versions of them.
For those of us that don’t have the time to manually trace and convert scans of signatures, there are automatic alternatives that have a leg up on both labor and time, the most reliable of which is Scan2CAD. In this article, we’ll discuss the process of inserting your signature into CAD drawings without having to resort to manually tracing them on your CAD program.
Table of Contents
Video tutorial: Converting your signature for CAD
In the following video, we demonstrate how to convert an image of your signature to a CAD format using Scan2CAD.
1. Getting the right source image
With any conversion process, the number one most important factor in getting high-quality output is the initial quality of your source image. With scanned copies of a signature, make sure that the hard copy was scanned at 300-600 DPI. With low DPI scan settings, you risk getting a signature that would be too pixelated to accurately vectorize.
Aside from the scan settings, make sure to also take the time to check for any unwanted marks, smudges, or creases on the paper you’re scanning. As much as possible, you want nothing but the signature visible on the paper you’re planning to scan.
In short, just take the time to make sure you have a good initial copy – something you wouldn’t mind putting on official documents. You’re only going to get something as good as you put in.
2. Cleaning the raster image
After opening up the chosen source image on Scan2CAD, we’ll have to do a few more tweaks to optimize it for conversion. Every individual signature is different, but the basics of cleaning up any scanned image you’re looking to convert are – black and white, de-speckle, and smooth.
For an efficient and clean conversion, black and white images are preferred by the software. Even when you’ve scanned a visually black and white image, the scanner will still tend to pick up the tiniest hints of gray tones and other colors all over the paper, so always make sure to tick the ‘Threshold (Black & White)’ box if it can be ticked.
And just to cover our bases in case the original source image wasn’t quite clean yet, try to tick ‘Remove Speckles & Holes’ as well as ‘Smooth’ just to make the raster image that much crisper and cleaner.
Do note that if these tools still don’t cut it, you can manually erase and add drawing elements onto the raster image with the editing tools at the left of the Scan2CAD interface.
3. Conversion settings
There are a couple of settings you can play around with when converting your raster signature. Among the three available Vectorization Methods, you’re going to want to try Outline and Solid. Both will produce results you can effectively use in your CAD program, but we’ll go over their specific attributes in the next steps.
The Vector definition slider is something you’ll want to adjust. The lower the value, the “sharper” the vector output. That is, it’s going to be more similar to the original raster image. The higher the value, the “smoother” the image. So depending on the quality of the original source image, you’ll want to find the sweet spot. Clicking on the Run button will show you a preview of the converted image.
For the rest of the conversion options, try to untick “Identify Circles” since there are not identifiable perfect circles in most signatures and then you can leave the rest of the options as is.
4. Converting to Solid
The enclosed or partially enclosed negative space in written down letters are called counters. So imagine the letter O as a black circle and its counter as a round hole that was cut out of it.
Now, the reason we’re giving you the proper term for that enclosed negative space is so that you understand when we say that Scan2CAD doesn’t technically recognize these counters or negative spaces as cut-outs. Rather, what Scan2CAD does is it recognizes these counters as white solids and then puts those white solids on top of black solids.
Imagine the O from earlier except instead of cutting out the counter in the middle, you put another solid circle, this time white, on top of the black circle.
There are some technical reasons for letter Scan2CAD to do that, but suffice to say it makes the conversion process smoother and simpler.
This has essentially the same output as the Outline option of conversion, provided you opt not to convert all black vector objects into white ones while saving (more on that shortly). But if this isn’t what you were looking for, let’s try out the other vectorization method.
5. Converting to outline
As the name implies, choosing the outline option simply creates a vector outline around the black parts of the signature.
Although this might not look complete now, what you can opt to do is export this into your CAD software and then proceed to fill out the insides of the outline with a solid hatch. It’s a relatively fast process and you don’t need to worry about solid overlays anywhere.
6. Final edits
As with the original raster image, you can manually edit the produced vector objects manually with the tools on the left side of the Scan2CAD interface.
Do note that these are meant for minor rectifications, mostly to erase any stray speckles anywhere in the image.
If you prefer, you can also use the scale tool to try and set an initial size for the produced vector image. But you would probably have an easier time doing that in your preferred CAD program afterward.
After all the edits have been made, the last part would be to save the newly converted vector file. At this point, you can choose the DXF and DWG file formats and save it under its appropriate file name. But you can also save the vector file to any popular vector format such as G-code formats including .CNC , .NC and .TAP.