PCX without RLE (uncompressed)

[giner]

It's not possible to convert bmp to pcx without RLE compression

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$ convert test.bmp test.pcx; file test.pcx
test.pcx: PCX ver. 3.0 image data bounding box [0, 0] - [590, 117], 8-bit colour, 72 x 72 dpi, RLE compressed
$ convert -compress none test.bmp test.pcx; file test.pcx
test.pcx: PCX ver. 3.0 image data bounding box [0, 0] - [590, 117], 8-bit colour, 72 x 72 dpi, RLE compressed
$ convert +compress test.bmp test.pcx; file test.pcx
test.pcx: PCX ver. 3.0 image data bounding box [0, 0] - [590, 117], 8-bit colour, 72 x 72 dpi, RLE compressed

[fmw42]

try

convert image.pcx -compress none image.bmp

see http://www.imagemagick.org/Usage/basics/#cmdline

Don't know if that will help, but it is the more correct syntax.

[giner]

try

convert image.pcx -compress none image.bmp

see http://www.imagemagick.org/Usage/basics/#cmdline

Don't know if that will help, but it is the more correct syntax.

Do you mean convert image.bmp -compress none image.pcx? It produces the same result.

[fmw42]

Do you mean convert image.bmp -compress none image.pcx? It produces the same result.

Sorry I had it backwards. But I am not a Windows expert so know little about Windows file formats. I am on a Mac. You my need help from a windows expert or the IM folks.

[giner]

Do you mean convert image.bmp -compress none image.pcx? It produces the same result.

Sorry I had it backwards. But I am not a Windows expert so know little about Windows file formats. I am on a Mac. You my need help from a windows expert or the IM folks.

Windows? I'm not a windows user
Thanks for helping. Anyway I think this is a bug.

[Drarakel]

The RLE compression is hardcoded (in pcx.c). I wouldn't call this a bug, as it's the intended behaviour in ImageMagick (and changing this would require a rewrite of some parts in the concerning method). I think, that's similar to GIF - that format also can't be saved without compression anymore in IM.
But I agree that it would be preferable if one could change these things at the commandline.

[el_supremo]

The PCX coder always writes the image with RLE compression.

Pete

[fmw42]

The PCX coder always writes the image with RLE compression.

Pete

Pete,

That was my thought also, but according to http://www.fileformat.info/format/pcx/egff.htm, uncompressed seems to be permitted even if the IM coder does not permit it or is IM using some delegate for that?

Fred

[Drarakel]

As far as I can see, it's all in coders/pcx.c (including the compression, which gets done in the PCXWritePixels method).

[el_supremo]

The IM coder writes the file, there's no delegate.
This file http://www.fileformat.info/format/pcx/egff.htm says:

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PCX files, however, always contain encoded image data, and currently the only valid value for the encoding field is 1.

This file http://www.qzx.com/pc-gpe/pcx.txt, which is supposed to be ZSoft's documentation of the PCX format, only talks about the file being encoded. It does not explicitly say anywhere that an uncompressed file is an option.
However, I modified my version of IM so that the coder will write an uncompressed PCX image and converted the rose: image to uncompressed rose.pcx. IrfanView and XnView can display the file but Paint Shop Pro can't.
@Magick: Let me know if you want my code to allow uncompressed PCX.

Pete

[fmw42]

Pete,

All I looked at was the table at the top of the file referenced above where it says:

Compression RLE, uncompressed

Fred

However, it is likely that Magick will take your code and allow IM to make uncompressed PCX files.

[magick]

We can reproduce the problem you reported and have a patch in ImageMagick 6.6.4-0 to support PCX compression. Thanks.

[giner]

Thank you very much for the quick fix!

Stas