Sometimes it's good to keep in mind that each builder designs their scanner for their own needs. In this case, the design intent was to go into archives and scan historical texts one at a time, by hand. As Atoha_SPB said:bnz wrote:The thing I am wondering about in this overall design is the following: it seems not very convenient to me to switch pages or scan the other respective side of the page. The other thing is that nothing mechanical seems to hold the book in position. It looks like the book - depending on what kind it is - would easily fall off the glass if you don't secure it with your hand. I would fear that this may probably mean that you'll have varying quality due to possible movements even if you use a fixed length lens.
Generally speaking, there is no quality problem if the book moves a little, it just means that cropping in post processing steps becomes a little more complicated.Antoha_SPB wrote:So far I am making scans of the crumbling books holding them by the hand from the bottom of the vertical side and turning the whole plexiglass module with the books very accurately.
Well, many builders have quality targets where we need to use all 10 megapixels of some camera to get 300DPI resolution. And many builders don't like to force the spine of a book open in order to have it flat. But generally, the problem is that a 550D -- without a lens -- is about $7-800. For that price, it is possible to buy two EP-1s or 7 Powershots, so for a long time many of us have preferred to use Powershots for their low price and many advantages.bnz wrote:Here are a few thoughts that I have. The first thing is (my Canon 550D is currently in repair so I cannot test) that I am wondering why photographing double-sided pages is as unpopular. I have made a few tests with the Panasonic cam above and scan tailor and the results are reasonable good. I image with the 18 megapixels of the 550D / Rebel T2i with a fixed length lens as opposed to the 9 megapixels of the Panasonic pocket cam, this should yield pretty reasonable results. I haven't done any batch tests of scan tailors capability to solidly recognize the middle of the two-page picture though. It might mean some manual work in the post processing.
There is also a resolution problem. You never actually use all 18mpix. Your edges will be filled with empty space, and you will lose some because the format of the book will never be the same as the sensor. When you get down to it, you may only get 3-5mpix for each page. Depending on page size, that may be plenty, but for some tasks it's not the right approach. I want to be clear here -- I think that ANY quality is acceptable, if YOU find it acceptable. If you're going to be reading on a phone, you don't need 300DPI. And depending on what you're scanning, having something just legible is alright. But the point is that it might not work for everyone, or many people...
That said, there's no reason YOU shouldn't take this approach. There have been a few single-camera scanners. One recent one was Will1384's scanner, though I think there have been others. Follow his build progress here:
http://diybookscanner.org/forum/viewtop ... t=30#p5093
I really love his work!
We're not really afraid of patents though many of us, myself included, won't deliberately patent anything or use patented things. It goes against our Open Source approach where we share ideas freely. Check out Will1384's build and see what you think.bnz wrote:The second thing I would think about is making a construction similar to that of the CopiBook scanners (see youtube). I am not sure whether you guys avoid a design like that due to fear of violating patents or something like that (would that even matter if you build a thing like that for private use?), but it seems pretty straight-forward to me to have a construction with two plates next to each other that somehow be adjustable to the book binding. In addition, I would think about a straight glass plate above that would flatten the pages in a construction similar to the new standard scanner so that it is easy to move it up and down, but not in a triangular form, but just flat. These are just some ideas, maybe someone with a little more experience can explain to me what he thinks about this kind of design.
Generally if you have questions this general, consider starting a new thread talking about how you'd like to build a scanner and people will pile on with links and input.