> On Feb 11, 2018, at 12:10 PM, Timothe Litt <l...@ieee.org> wrote: > > Lighting is an issue, as is compensating for keystoning and other > misalignments. Most cameras don't have a standard remote trigger interface - > one of the pointers I provided loads modified firmware into cameras from one > manufacturer to make this work. If you look at digital camera reviews, > you'll see that the lenses have varying degrees of artifacts, especially at > the edges. So you need to find and zoom to an area that's relatively "flat" > & doesn't need a lot of correction. While depth of field will help, it also > will result in apparent font size changes as paper sways forward and back. > If you stop that, you simplify the OCR - and don't need as much depth of > field.
Even with a copystand getting everything lined up correctly is a pain. I have a little trick I use when using a DSLR with a Macro lens on one of my copystands. I have a pile of heavy/flat books to get enough height that I can rest the rim of the lens on the books. I use this to get it parallel to the surface of the stand, then tighten the camera down. I’ve never tried doing this with anything that needs OCR’d. I’ve mainly used the setup for glass slides, but the next up for me will be some 200 year old art, that I’ve been asked to reproduce. Zane
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