A2-A1 scanner

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spamsickle
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Joined: 06 Jun 2009, 23:57

Re: A2-A1 scanner

Post by spamsickle »

I've tried using Hugin to stitch two halves of a page together, and my results were unusable. There may be a way to tell Hugin how to do it right that I just didn't find, but I suspect we will need custom software written specifically for stitching text.

The problem with Hugin is that it's designed to make transitions appear seamless. It seems to use mostly squash/stretch and fade, kind of like a morphing tool. I couldn't make it recognize and preserve text, or even match the identical text in one picture to the text in the next, no matter how many control points I used. It works for landscapes and architecture, so you'd think it could handle text, but I couldn't make it happen.

Admittedly, I only played with it for a couple of hours, and hadn't been a Hugin user prior to this experiment, so someone more familiar with the tool might be able to use it more effectively. This tutorial seems to be claiming it's possible, and they're doing things I didn't do (like specifying different lenses), so it's probably worth a shot. The result looks good, but there may be a reason he's not working with text.

Skimming the tutorial, it seems like a lot of work to get one output image. If it can be made to work for one page, will it still be worthwhile to go through this for an entire book? If there was enough consistency between pages, could one setting be used to stitch a whole chapter? A whole book?
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daniel_reetz
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Re: A2-A1 scanner

Post by daniel_reetz »

The Hugin interface defaults are seriously optimized for panoramic capture, and it's necessary to make a bunch of special adjustments for stitching two flat pages. I'm starting to get interested in this kind of thing again, so maybe, Spam, once I get our last work session online, we should have a little get-together over stitching multiple images.

The basic procedure in this case is to remove lens distortion, "pin" the images together using "control points" or auto-located SIFT features, and then to output the two images transformed to match each other. Hugin can blend using a variety of output blenders, or not blend at all, so the particulars of each image case can be compensated for. I think in this case the "enblend" engine is more appropriate than the gradient domain or averaging stuff they do for panoramas.

The good thing about Hugin is that if you can go through all the trouble to make the images work out one time (which can be significant effort/pain, I've had my share of fighting with it), you can get it to work every single time after that.
gusunavarro
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Re: A2-A1 scanner

Post by gusunavarro »

Hello
Iam new

I need scanning newspaper format A2.
My question is know if these camera Nikon D3500 with 18-55 mm is good for scanning newspaper and 24 mp is for these format?
https://www.nikonusa.com/en/nikon-produ ... d3500.html

thanks very much
gus
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LA2
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Re: A2-A1 scanner

Post by LA2 »

Hello, gus, two years later. The Nikon D3500 you mention has 24 megapixels or 4000 x 6000 pixels. For the short edge of an A2, 420 mm or 16.5 inches, that will give you a scanning resolution of 240 dpi. If this resolution is good for you, you're fine. But for newspapers with fine print you probably want more than 300 dpi. My estimate is that 24 MP is good for A3 (297 x 420 mm, 11.7 x 16.5 inches, 340 dpi). For A2, there are few good solutions. Cameras with 48 MP are in a very different price range, unfortunately.
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