[Image-SIG] Converting tiff to PNG
Christopher Barker
Chris.Barker at noaa.gov
Mon Aug 6 21:06:27 CEST 2007
Jeff van Aswegen wrote:
> convert img.tif -monochrome +matte -depth 8 -quality 100 img.png
This looks like you've got an 8-bit monochrome tiff.
From a quick glance at:
http://www.w3.org/TR/REC-png-multi.html
it looks like PNG should support that, but it is mostly used for 24bit
RGB and 32bit RGBA. I'm guessing that perhaps you're getting an RGB PNG,
which would explain why it's larger than the Tiff.
It does seem like the flags you're passing into convert should be doing
this right, but I'd check to see if they are.
You might see what PIL gives you, making sure you use the 'L' mode (8
bit greyscale)
-Chris
--
Christopher Barker, Ph.D.
Oceanographer
Emergency Response Division
NOAA/NOS/OR&R (206) 526-6959 voice
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Chris.Barker at noaa.gov
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