[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:


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)


Christopher Barker, Ph.D.

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Chris.Barker at noaa.gov

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