Request For Help: DIYBookScanner FAQ

[daniel_reetz]

We really should have some kind of public-facing FAQ, perhaps on the home page as well as the forums and wiki. I suggest we split them into "Hardware" and "Software". I also suggest that we link to threads that better answer the question. For example, spamsickle has written out his software workflow several times, or fbonomi's aperture tests, etc etc.

This list is far from exhaustive. Feel free to add questions, change these questions, or change my answers. Also, please add any relevant links to any question.

I am just going off the top of my head here:

Hardware:

Why should I build one of these when we have flatbed scanners?
Why should I build one of these when I can just saw off the spine and sheet-feed scan it with a Fujitsu ScanSnap?
What other benefits does this system have?

How hard is it to build one of these scanners?

It depends. You can build one from styrofoam and tape in a couple hours, or you can build one from hardware store material over a long weekend, or you can go completely crazy and build one as elaborate as you like. The difficulty really depends on you and your needs, but we have people who've never soldered or built anything with working scanners, and we have mechanical engineers with no scanners (yet). Go figure. You can do it, we will help.

What is the average cost of building one of these scanners?

Again, it depends. Daniel's first scanner cost about $300, but he had tools, tape, and glue and got most parts from the trash. Cameras are the most expensive part -- by using just one you can cut a hundred bucks or more from the cost. If you have a single book of interest, it may make good sense to make a scanner from cardboard or junk and use a single camera, which shouldn't cost you much at all.

Are there any sample images?

Daniel posted some here. However, the community at large hasn't shared much just yet. This is top priority.

Does it work well with OCR?

Yes. Some of our members use it just to turn books into audiobooks. However, we don't provide OCR software. We just provide the plans to produce usable scans. The limiting factor is the quality of commercial OCR software.

Do you need expensive cameras? Can you use webcams?

Many of us believe that the Canon Powershot line is the best compromise in terms of price and performance. You can always get better cameras -- quality will only increase. However, though many, many people have asked about the so-called 8mpix webcams, no-one has done any testing, so we can't recommend them.

What cameras work?

agh.

Has anyone made a page turner?

No, though it comes up all the time. Be the first!

What are the appropriate camera settings?

Depends on your setup. Fixed aperture, fixed exposure, low ISO, appropriate white balance... anything SDM specific goes here.

Can I trigger my cameras without custom firmware?

Yes, you can use: (list of things you can use)

Can I use lights other than halogens?

Yes, you can, and nobody cares about Daniel's arguments to the contrary, they seem to get fine scans anyway (link)



Software:

What software do you use?

We have been working with Tulon, the author of Scan Tailor. Many of us feel his software is the best solution for handling images from these scanners.

Does Scan Tailor run on Linux? Windows? Mac?

Scan Tailor runs on Linux, Windows, and Mac.

Does it to OCR? How do I do OCR?

Scan Tailor does not do OCR.

???

[Misty]

Very good idea. Here's a few contributions I'd make:

Why should I build one of these when I can just saw off the spine and sheet-feed scan it with a Fujitsu ScanSnap?
One reason is if you're scanning old, rare or unique books/documents. Some of our members, like Misty and Ann, work with archival materials that are in very fragile shape, which obviously can't be chopped open or even flattened onto a flatbed scanner.

Appropriate camera settings
If your camera supports manual ISO, always use the lowest setting. For example, on a Canon PowerShot G10, always use ISO 80. Low ISO ensures the minimum possible level of noise in an image.

White balance: You can get the best results by using lights with a known, standard temperature, which can let you tune your white balance to the exact properties of the light. See my post about lights and white balance. If that's unavailable, you can manually record a white balance on many cameras by using the "custom white balance" mode; aim the camera at a white piece of paper that fills the frame, and record a white balance setting based on the lighting environment. This is not as accurate as using the temperature of the light, but it might be good enough depending on your needs.

I'd give other camera advice, but I think my G10 is atypical compared to the cameras most people are going to be using, and wouldn't be terribly useful.

Can I use lights other than halogens?
It might help to link to my thread about using daylight CFLs. The ISO standard in professional digitization is D50 lights (lights with a colour warmth of 5000K), but these aren't usually available to amateurs or small institutions at a reasonable price. I settled on 6500K lights that are similar to the D65 standard (but not actually marketed using the D65 term) because they're easily available at the local hardware store for cheap, and allow for very accurate, reliable colour results.

I would strongly recommend against telling people to use halogens. Halogens are very harsh, high-UV lights, which will "age" paper unnecessarily and irreversibly. They should never be used that close to paper, especially for scanning old, rare or brittle books. You can make halogens safe by using expensive UV filters, but at that point you might as well be using something else to start with.

Can I trigger my cameras without custom firmware?

Depends on the camera. Some cameras support a "remote live view" mode which allows you to remote control the camera via USB from a computer. However, this feature is mostly only available on DSLRs and some high-end PowerShots, and is limited to JPEG only on the PowerShots that support it.

Some cameras support remote shutter releases out of the box, though a lot of cheap cameras are missing this feature. For example, the Canon PowerShot G series and EOS series use a remote called the RS60-E3 (or clones thereof). Remotes aren't usually compatible with each other, so check what model your camera wants. You can usually get compatible 3rd party remotes for fairly cheap.

[rob]

Help! All my scans come out crooked, with keystoning, with curvature, with distortion. What does page dewarping?

We've been working on various algorithms to help with page dewarping, but the results have been less than satisfactory. Even approaches in the research papers seem to be overly compute-intensive, limited to a specific type of book or camera setup, or both. So, we currently have no suggestions for handling automatic page dewarping.

[daniel_reetz]

I passed this on to KoulevPrime, we'll be working together on some FAQs! It's gonna be great.

[koulevprime]

Good stuff so far! I'll use this page to ask questions to the entire forum.