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On Mon, 1 Mar 2021 11:50:35 +0000, Wols Lists wrote: |
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> I've got a bunch of scans, let's assume they're text documents. And |
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> they're rather big ... I want to email them. |
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> |
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> How on earth do I convert them to TRUE b&w documents? At the moment they |
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> are jpegs that weigh in at 3MB, and I guess they're using about 5 bytes |
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> to store all the colour, luminance, whatever, per pixel. But actually, |
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> there's only ONE BIT of information there - whether that pixel is black |
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> or white. |
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> |
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> I'm using imagemagick, but so far all my attempts to strip out the |
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> surplus information have resulted in INcreasing the file size ??? |
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> |
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> So basically, how do I save an image as "one bit per pixel" like you'd |
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> think you'd send to a B&W printer? |
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$ convert input.jpg -threshold 50% output.png |
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should do it, you may need to play with the threshold setting. The file |
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command reports the output file as being "1-bit grayscale". |
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You can also use -monochrome but that will produce a dithered image, |
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that's probably not what you want judging by your description. |
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-- |
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Neil Bothwick |
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If we aren't supposed to eat animals, why are they made of meat? |
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