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[Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge
From: |
Mike Miller |
Subject: |
[Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image |
Date: |
Fri, 24 Jul 2015 21:49:58 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Firefox/38.0 |
Follow-up Comment #16, bug #45565 (project octave):
So I analyzed the BMP header fields more closely and found that Octave creates
a BMP using RLE compression by default, while the file you have attached that
you say works is not using any compression. This agrees with the info I saw
from PIL.
So my simple thought at this point is that Octave needs to tell GraphicsMagick
to write uncompressed BMP files, if GraphicsMagick exposes that knob and
allows a way for Octave to set that. This seems like a Matlab compatibility
item, based on https://www.mathworks.com/help/matlab/ref/imwrite.html saying
that BMP files are always uncompressed.
This is independent of whether imwrite with a uint8 argument should write
8-bit BMP files by default or whether it requires a colormap argument. I can't
decipher Matlab's help page for imwrite to figure out if that's a separate
compatibility issue.
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- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, (continued)
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Ian Journeaux, 2015/07/17
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Mike Miller, 2015/07/17
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Ian Journeaux, 2015/07/17
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Ian Journeaux, 2015/07/17
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Carnë Draug, 2015/07/17
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Carnë Draug, 2015/07/20
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Ian Journeaux, 2015/07/20
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Mike Miller, 2015/07/20
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Ian Journeaux, 2015/07/20
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image, Mike Miller, 2015/07/24
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit iamge to BMP creates a 24 bit image,
Mike Miller <=
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit image to BMP creates a 24-bit image, Mike Miller, 2015/07/24
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit image to BMP creates a 24-bit image, Ian Journeaux, 2015/07/25
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit image to BMP creates a 24-bit image, Carnë Draug, 2015/07/28
- [Octave-bug-tracker] [bug #45565] Using imwrite to write an 8-bit image to BMP creates a 24-bit image, Carnë Draug, 2015/07/28