Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Preserving colored text

Discussions, questions, comments, ideas, and your projects having to do with DIY Book Scanner software. This includes the Stereo Data Maker software for the cameras, post-processing software, utilities, OCR packages, and so on.
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Re: Preserving colored text

Post by kempelen » 10 Feb 2012, 07:55

This method is very nice, but if colors are too similar, they don't work well, even with adjusting the percentages. When colors are similar, black won't be fully black, and the other color is not fully that color.

If this feature could be integrated into ScanTailor and that would be excellent. But, to clearly distinguish between color and black text, we may have to use manual area selection. There could be a new tab "Color text" tab on "Output" stage, where we can draw rectangles (or shapes) to mark colored areas. This may include solid fills too, not only text. (For example colored borders need 4 rectangles.)

When areas are defined, the program would - somehow - detect the ruling color of each area and then do "threshold" operation like with B&W, and finally fill Black pixels with the detected ruling color...

The color may need to be applied to all pages, so minor differences in the scan would still result in the same color output. (But this part could be done in ImageMagick with the method described here.)

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