QUALITY SCANNING:
Creating high quality scans for raster to vector conversion
... Continued. [Previous page]
Always check your scan
After scanning, check your scan. It is always better to discover problems at the time of scanning rather than six months later when the drawing has been destroyed.
Make sure that the full extents of the drawing have been captured.
Make sure that the scan is not skew.
If the scan is skew, rescan the drawing straight. While you can deskew scans after the fact, deskewing a scan can decrease its quality, particularly if the scan is very skew.
Make sure that any text is legible.
Make sure that text characters and entities that are close together are separated by clean white space.
If they touch partially or completely, you need to experiment with your threshold settings and or scanning resolution.
Make sure that the drawing lines are solid, not broken.
If they are broken, you need to experiment with your threshold settings and or scanning resolution.
Conclusion
There is no doubt in our mind that scanned image quality is generally poor and that many of the millions of archived scans of valuable drawings that exist are mediocre at best - despite being captured on state-of-the-art large format scanners. Such images are not going to give their owners the benefits of automatic raster to vector conversion. Judging by the scans we receive, some are not even good enough for viewing or printing purposes.
By following the steps in this article - scanning black and white drawings in monochrome not colour, setting an appropriate threshold and resolution, not saving your scans as JPEG and always checking your scans - you can expect to create high quality scans that - assuming your drawings are suitable - you will be able to vectorize using Scan2CAD raster to vector conversion software and other raster to vector converters.
Even if you are not planning to convert your images you will be safe in the knowledge that the information on your drawings is legible and usable for whatever you may need them for in the future. Quality wins every time.
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Q&A: ASK AN EXPERT
Q: I've got a Return to Factory Warranty but I've lost the box. Help!
A: There is little you can do except contact the factory and ask them if you can drive the scanner over to them securely protected with wrapping in the back of your car.
Under the terms of a Return to Factory Warranty you are usually required to return the scanner to the factory in the original packaging. This is to ensure that it is fully protected in transit to the factory and back again.
As scanner boxes are huge the temptation to destroy them is great. However if you return your scanner to the factory wrapped in bubble-wrap, blankets and brown paper it will probably get damaged en route and you will be liable.
In our experience many resellers do not advise their customer of the requirement to keep the box. Equally, most customers do not read the fine print of the terms and conditions of the warranty. Finally, the terms and conditions of the warranty itself often fail to highlight this very important requirement.
We have heard about a customer who bought a flatbed model of a leading brand of scanner. The box was destroyed in the unpacking. On start-up the scanner failed. The customer phoned the distributor who sent an engineer to examine the scanner. The engineer concluded that the scanner was repairable, not Dead on Arrival. Because it was repairable, the scanner had to go back to the factory to be fixed.
As the box was destroyed, it was impossible for the customer to return the scanner to the factory under the terms of the warranty. The customer was advised by the distributor that if they wanted the scanner repaired free under the terms of the warranty - it was that or not at all! - they had to buy a box from the distributor for £150.
Whilst we disapprove of this response to the customer's problem - we think that issues like this are not the customer's fault and should be quickly, sensitively and responsibly addressed by the manufacturer or distributor - these are the terms and conditions that come with the warranty when you buy a large format scanner.
We're happy to answer questions! Click here to email us.
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