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> Capture, Black and white
JimL
post Feb 27 2009, 12:39 PM
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How can I prevent a B&W text capture (prep for OCR) from being instantly converted to deep color?

Thanks
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Peter
post Mar 3 2009, 02:19 PM
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QUOTE (JimL @ Feb 27 2009, 12:39 PM) *
How can I prevent a B&W text capture (prep for OCR) from being instantly converted to deep color?

Thanks


The screen capture function always uses the bit depth of the display. If the captured data does not contain more than 2 colors, you can simply do a Color->Convert to->Indexed 256 (or Black & White) and you should end up with a monocrome image.

Thanks,
Peter


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Peter Nielsen (peter@pmview.com) "If you can dream it, you can do it" JFK.
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JimL
post Mar 3 2009, 04:25 PM
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QUOTE (Peter @ Mar 3 2009, 02:19 PM) *
The screen capture function always uses the bit depth of the display. If the captured data does not contain more than 2 colors, you can simply do a Color->Convert to->Indexed 256 (or Black & White) and you should end up with a monocrome image.

Thanks,
Peter


The output needs to be black and white, but I get this gaining or losing of edges when I convert out of deep color. Should that vary with the format? So that BPM might work better than JPG?
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Peter
post Mar 5 2009, 11:29 AM
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QUOTE (JimL @ Mar 3 2009, 04:25 PM) *
The output needs to be black and white, but I get this gaining or losing of edges when I convert out of deep color. Should that vary with the format? So that BPM might work better than JPG?


JPEG cannot store B&W images. JPEGs are either 8-bit (grayscale) or 24 bits and is a poor choice for storing B&W material.

GIF, BMP, and PNG can store B&W. One of the most effective way to store B&W is to use TIFF with CCITT FAX4 encoding. A page that is a megabyte saved as BMP will shrink to a few kilobytes when saved as TIFF CCITT FAX4. (PMView can do this!)

Thanks,
Peter


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Peter Nielsen (peter@pmview.com) "If you can dream it, you can do it" JFK.
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