Difficult Images

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Gordon Cheung

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Aug 18, 2014, 7:20:01 PM8/18/14
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Hi, I'm currently trying to get OCR to recognize images that I am taking from a camera, from small pipes. Is there anyway to recognize images like these? I'm currently getting no output in the generated Text file. I can convert edit the images if need be, but in which way will allow Tesseract to recognize the single letter? All of the images that I will be generating will look like this one. Just one image inside of a circle.

Thanks for any help!
A1.jpg

David Cuenca

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Aug 19, 2014, 5:47:16 AM8/19/14
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Have you tried to do some pre-processing with http://opencv.org/ ?

Cheers,
Micru


On Tue, Aug 19, 2014 at 1:20 AM, Gordon Cheung <itsgor...@gmail.com> wrote:
Hi, I'm currently trying to get OCR to recognize images that I am taking from a camera, from small pipes. Is there anyway to recognize images like these? I'm currently getting no output in the generated Text file. I can convert edit the images if need be, but in which way will allow Tesseract to recognize the single letter? All of the images that I will be generating will look like this one. Just one image inside of a circle.

Thanks for any help!

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Art W Rhyno

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Aug 19, 2014, 9:05:44 AM8/19/14
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Hi Gordon,

I ran into something like this once with a set of images from microfilm. It might not work on all of your images but one thing you might try is to use gimp for preprocessing. You can script gimp if there is a set of steps that achieves a desired result and in this case, try opening the image, reducing it by 75%, do a color selection based on black, and copying the results into a new image. I think you would often get a result like the attached. If so, you might be able to eliminate the outside color and leave the letter on its own. If the images have the letter in close to the same position and size then you might be able to extract the letter based on coordinates.

art

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