Sometimes people contact us to say they're having difficulties using Scan2CAD to convert a logo. When they email us their problem logo we usually find that the root of the problem is one of the following:
These problems are detailed below, along with the best way to get a logo scan that will give you a good conversion.
The JPEG file below, "Jane's Flowers", looks fine on the web, because that's what it's been
designed for - web display.
However, if you load it into Scan2CAD, Photoshop, Paintshop Pro or any similar program and zoom into the "r" in
the word "Flowers" this is what you'll see:
Looked at close up, the "r" is not discernable even to the human eye. It's not surprising
that Scan2CAD has difficulties with this type of logo.
An image with an intended end use of web display requires completely different attributes from an image with an intended end use of vectorization.
Images downloaded from the web are generally unsuitable for raster to vector conversion.
Logo artwork tends to be small and this means that we often see logos that have been scanned at too low a resolution. While we recommend 200 to 400 dpi as an optimal scanning resolution for most drawings, it is too low if the drawing you're scanning is a small logo.
To illustrate the problems you're likely to encounter when scanning a small logo we drew the "Jane's Flowers" logo artwork so that it measured approximately 1.6" x 1" (4cm x 2.5cm) in size.
Below is the "r" in the word "Flowers" after scanning the logo artwork at 300 dpi. You can see that the outline
of the "r" is very jagged. This means that it is too low resolution.
You will not be able to produce a good vectorization from this image.
After scanning at 1200 dpi the logo outline is much smoother, but unfortunately scanning it at a higher resolution has resulted in a new problem.
At the higher resolution the scanner has picked out tiny details that are not visible to the human eye when viewing the
logo on paper. Because the artwork is so small, these details are large in relation to the size of the logo. This means that
the corners of the "r" have become rounded and the lines of the "r" are bumpy
instead of straight and smooth.
You will be able to produce a usable vectorization from this image, but the vectorization won't be as good as it
could be (see Getting the best possible scan for logo vectorization).
Note that the rounded corners of the scanned "r" have been reflected in the vectorization by chamfers.
To sharpen the corners, do the vectorization again, but before you do it go to the Type Menu, select Settings and enter
a value for Corner Snap. Scan2CAD will then remove all chamfers shorter than the Corner Snap and join the main lines
together, giving sharp corners.
To conclude, you will never be able to get a really good scan from small original artwork and this will be reflected in the vectorization results you can expect.
To get the best possible scan for logo vectorization, start with bigger artwork.
We drew the "Jane's Flowers" logo artwork again, but this time we drew it bigger so that it filled a letter size / A4 sheet.
Here is the "r" in "Flowers" after scanning the bigger logo at 300 dpi. The scanned outline is smooth
and clean.
Note that to get a good scan like this your original artwork must be large. You cannot start with small original
artwork and enlarge it on a photocopier before scanning. This will result in a scan that is no better - and that is
probably worse - than the scan you would get if you scanned small artwork at a high resolution.
Once you have a smooth clean scan you will be able to vectorize it as follows.
This will produce a vector image made up of lines and Bezier curves:
If your CAD/CNC program doesn't support Bezier curves you can convert them to polylines or arcs on export.
Alternatively, you can vectorize the scan as follows:
This will produce a vector image made up of lines and arcs.
If you can't see any vectors after you've done the vectorization, press C on your keyboard to display the vectors in different colors.
If you still can't see any vectors, or if your vectors look something like this ...
... it's likely that your image is grayscale or color, even if it looks
black and white. Do the following:
This will turn your image into black and white. Turning a grayscale or color image into black and white often gives it ragged edges and leaves white holes in the black areas, so ...
Now repeat the vectorization.
Once you've scanned your logo, don't save it as JPEG as this will almost certainly reduce the quality of your scan. Save it as TIFF or BMP.
Is your raster image suitable for vectorization? Work through our Raster Quality Checklist!
Scan2CAD support is free.
If you have a question about Scan2CAD or are experiencing a problem, please email us.
If you have a question about converting a particular raster image please attach it to your email and we'll have a look at it and advise.
We answer every email we receive. If you do not receive a reply from us, please check your spam bin.
"Many thanks for the great advice. Your rapid response to problems/questions and credible suggestions are unmatched when compared to other software firms we've dealt with. Thanks for the high standard of service."
P. Michor
"What a tremendous program. It's a real time saver!"
D. Janelle
To get raster to vector and scanning hints and tips, large format scanner news and views and all the latest about Scan2CAD, enter your email address below then click Subscribe.