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Ask HN: Open source OCR library?

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Re: Ask HN: Open source OCR library?

#91

Post by ajross »

jahewson wrote: post #21
t0 wrote: post #3

The accuracy of GOCR is very high and it doesn't require any learning. http://manpages.ubuntu.com/manpages/dapper/man1/gocr.1.html

GOCR is ok, certainly much better than GNU Ocrad, but I've had much better results with Tesseract.

GOCR is simple enough to install from your distro's repository and wrap into a script without fuss though. Tesseract is wildly more complicated to get started with.

If you're doing real time street sign recognition or involved with a book scanning and archival startup, investigate Tesseract for sure. But even then you'll probably want to prototype with gocr first.

Re: Ask HN: Open source OCR library?

#92

Post by loumf »

cinjon wrote: post #90
loumf wrote: post #44

Earlier quoted context omitted.

Abbyy, and most good commercial OCR, charge a runtime royalty based on the number of cores you are deploying to. Depends on volume.

Where do you see this? I'm actually thinking of buying the software right now and I explicitly asked what other charges are there besides the initial fee (~$100) and they said there wasn't any. Am I not asking the right question?

At my previous job we used them (on Windows).

I seriously doubt that it's just $100 -- but, I guess if you are making an application that you are just going to run yourself on a single machine, it would not cost much. The costs tended to increase with the number of computers you were deploying to. Or perhaps we used something more capable (does that come with all languages -- including Chinese/Japanese/Korean and RTL languages).

Re: Ask HN: Open source OCR library?

#93

Post by sandGorgon »

riordan wrote: post #59
sandGorgon wrote: post #5

http://www.danvk.org/2015/01/11/training-an-ocropus-ocr-mode...

Yep. Back when I was at NYPL Labs[0], we developed a bit of an obsession with OCR. It turns out that so much of it depends on the context of the documents, original scan quality (unpaper and deskewing be damned), typography, how much handwriting you're willing to suffer (can someone please pick up the work of applying Convnets to large handwriting corpora that aren't just MNIST?). A lot of this comes down to how much…

this is awesome! thanks for taking the time... Damn, HN really needs bookmarks

Re: Ask HN: Open source OCR library?

#94

Post by riordan »

bouyoul420 wrote: post #77
riordan wrote: post #59

Earlier quoted context omitted.

Yep. Back when I was at NYPL Labs[0], we developed a bit of an obsession with OCR. It turns out that so much of it depends on the context of the documents, original scan quality (unpaper and deskewing be damned), typography, how much handwriting you're willing to suffer (can someone please pick up the work of applying Convnets to large handwriting corpora that aren't just MNIST?). A lot of this comes down to how much…

Great list of links. You have done the research! Personally, I have used ocropy to great effect. Right now, I am moving beyond forms at work and researching cartographic map vectorization using deep learning techniques. There is little science papers on the subject however. Have you done any research on that by any chance?

Indeed! Map vectorization is one the things NYPL Labs is actively working on: https://github.com/nypl/map-vectorizer

It's designed to work primarily with old fire insurance atlases (e.g. Sanborns) and is a bunch of hand-tuned heuristics. But it powers Building Inspector (http://buildinginspector.nypl.org), which is where all the data is validated consensus crowdsourcing, providing ground truth for the data coming out.

Unfortunately (or perhaps fortunately if you're trying to get a Computer Science PhD) I haven't come across anyone applying deep learning to map vectorization either. Frankly, it could open up a whole new field with respect to historical mapping (among other things).

Would love to talk more about it and see how deep learning could be applied here. We always structured the outputs of Building Inspector so they'd be useful training sets for unsupervised or reinforcement learning so it could hopefully apply here as well.

Re: Ask HN: Open source OCR library?

#95

Post by cinjon »

loumf wrote: post #92
cinjon wrote: post #90

Earlier quoted context omitted.

Where do you see this? I'm actually thinking of buying the software right now and I explicitly asked what other charges are there besides the initial fee (~$100) and they said there wasn't any. Am I not asking the right question?

At my previous job we used them (on Windows). I seriously doubt that it's just $100 -- but, I guess if you are making an application that you are just going to run yourself on a single machine, it would not cost much. The costs tended to increase with the number of computers you were deploying to. Or perhaps we used something more capable (does that come with all languages -- including Chinese/Japanese/Korean and RTL…

Aye, I just had a back and forth with a tech rep there. They advised me at the end to contact sales to 100% understand, but the gist I got was that the FineReader Engine is $100 and it can do anything the SDK can do, but you have limited functionality in how it can operate with other programs (on Mac, all you get is Automator) and it can't be scaled to many cores. If you don't need that, then it seems to be a pretty damn good deal. Will talk to the sales rep first though.

What kind of problem were you dealing with? Were you bumping up against any constraints?

Re: Ask HN: Open source OCR library?

#96

Post by loumf »

cinjon wrote: post #95
loumf wrote: post #92

Earlier quoted context omitted.

At my previous job we used them (on Windows). I seriously doubt that it's just $100 -- but, I guess if you are making an application that you are just going to run yourself on a single machine, it would not cost much. The costs tended to increase with the number of computers you were deploying to. Or perhaps we used something more capable (does that come with all languages -- including Chinese/Japanese/Korean and RTL…

Aye, I just had a back and forth with a tech rep there. They advised me at the end to contact sales to 100% understand, but the gist I got was that the FineReader Engine is $100 and it can do anything the SDK can do, but you have limited functionality in how it can operate with other programs (on Mac, all you get is Automator) and it can't be scaled to many cores. If you don't need that, then it seems to be a pretty…

We were an image-processing SDK with OCR add-ons which were us reselling 3rd party SDKs with integration to our codecs and the processing code. It needed to be completely general purpose use in any .NET program (web, service, desktop, console, etc) since we didn't really want to get into usage with our customers (we had no royalties or usage restrictions on our part).

I think we opted for the customer actually obtaining their Abbyy license from Abbyy in the end because of the licensing mis-match. We sold just the wrapper.

Our parent company was a big user of Abbyy, and I think had a totally custom deal. They needed it for all of the language support and similarly wanted the full power to run it at high-speed and inside of .NET programs.

Re: Ask HN: Open source OCR library?

#98

Post by BlueberryYY »

totalcookie wrote: post #72
loumf wrote: post #44

Earlier quoted context omitted.

Abbyy, and most good commercial OCR, charge a runtime royalty based on the number of cores you are deploying to. Depends on volume.

Can you point me to some prices, per core / core-year?

This is from years ago, but it was $4,900 for an SDK license for development and testing, and then the runtime licenses that you actually deploy are negotiable depending on pages/month, cores, languages, and other options. I think if you're just buying 1 runtime license they try to make it so it is around $5K so the total deal size is $10K. But they are negotiable. Maybe mention if you're a startup.

They also sold Recognition Server which has fewer options to integrate with programmatically (it was only 'hot folders' at the time), and I think only runs on Windows, but costs less.

And their mobile OCR which is lightweight, designed to run on smartphones, they worked out deals where they get a percentage of revenue.

Re: Ask HN: Open source OCR library?

#99

Post by netheril96 »

hbornfree wrote: post #17

As others pointed out, Tesseract with OpenCV (for identifying and cropping the text region) is quite effective. On top of that, Tesseract is fully trainable with custom fonts. In our use case, we've mostly had to deal with handwritten text and that's where none of them really did well. Your next best bet would be to use HoG(Histogram of oriented gradients) along with SVMs. OpenCV has really good implementations of bo…

In my experience, CNNs offer the best performance. It is also easy to treat as a black box with many tunable parameters.

But the existing frameworks are mostly bad as an engineering product. Caffe, for example, calls `exit` every time an error occurs, including recoverable ones like files which do not exist.

Re: Ask HN: Open source OCR library?

#100

Post by totalcookie »

physcab wrote: post #81
totalcookie wrote: post #39

Earlier quoted context omitted.

Finereader engine Abbyy for Linux looks fine, but I can't find price data, is it <10k/year? One time license?

You can get Abbyy OCR Cloud SDK and its $0.10 per page (goes down with volume). http://ocrsdk.com/plans-and-pricing/

Thx!
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