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I would like to scan old text documents, and then destroy some of the originals.
Apart from spot-checking, what can I do to get an acceptably low scan failure rate? I would like to get a failure rate below perhaps 0.25% (after spot checks). I count as failures pages that are missed or are not legible.
This seems a difficult target to achieve. What can I do to reduce the rate of failures in the first place, so that I have less checking to do?
Related question (this question is about "QA" i.e. preventing failures, the linked question is about "QC" i.e. detecting failures): How to verify scanned page count and quality when using sheet feeder?
Use high quality equipment or scan all documents multiple times (in several batches) – Nifle – 2015-03-29T19:03:16.910
Call me silly but I hadn't thought of scanning multiple times. Why not make it an answer? "Use high quality equipment", on the other hand, is too vague to be useful. – Croad Langshan – 2015-03-29T19:39:31.597
Scanning is very consistent, unless you are talking about things like misfeeds. If a page is successfully fed, the result will be the same each time. You need to deal with the potential causes of illegible results. They won't be an issue for high quality originals. The sources are things like originals that aren't in good physical condition, or where the content is hard to capture due to fading, discoloration, background noise on the paper, content color that doesn't scan well (light colors, but especially blue), etc. Can you describe the originals? Solutions are specific to the problem. – fixer1234 – 2015-03-29T20:41:00.253
1In your parallel question "What features are important in a scanner + sheet feeder for old personal documents" you stated "I'm very unlikely to spend more than 500 UK pounds on hardware (and likely significantly less than this)". You might achieve your goals (price and quality-wise) if you have documents that vary only slightly. Otherwise your expectations at less than 500 GBP are overblown. The quality of a scanner (and the outcome of your scanning) is not only determined by the scanner's hardware but very much also by the quality of bundled drivers and software. – user291737 – 2015-03-30T12:33:58.013
@user291737: why is that overblown, when you consider that that error rate is after manual checks (and repeat scans)? This question is about how to reduce the pre-check error rate so as to make the manual checking less onerous, not to achieve 0.25% with no checking. – Croad Langshan – 2015-04-02T00:20:50.287
Because you wrote spot checks, i.e. a random sample of scanned documents. You don't mention your envisaged sample size but let's assume that a spot check is <10% of the total of thousands of pages (as you wrote in your other 2 questions). As you explained in your other question (http://superuser.com/questions/895454/what-features-are-important-in-a-scanner-sheet-feeder-for-old-personal-documen) your documents vary A LOT. At a budget of 500 GBP you get consumer grade or very basic professional grade scan equipment (hardware + software) that does not offer the amount of automation you look for.
– user291737 – 2015-04-03T11:17:40.793Right. Well, I'm open-minded, and somebody suggested giving each page a quick look by eye: seems quite workable. The documents are mostly fairly boring A4, or close to that -- modified the other question to make that clear (though really I think it would be better if the question were a little less explicit in the details, and answerers used their own expectations about the contents of typical home filing cabinets, since I suspect useful answers can still be given about scanners that handle a relatively broad workload and I'd rather the answers are useful to other people than just me...). – Croad Langshan – 2015-04-03T15:57:55.883