Legacy ImageMagick Discussions Archive

I generate millions of ARGB files using a C code and I need them in a "light" .jpg format as-well.
At the moment I use GraphicConverter (http://www.lemkesoft.com/) but as my ARGB files are piling up and getting bigger too I would like to run the conversion from the command line on the machine they are generated on.
The files have no header, they are produced on an Intel machine so their byte order is Little-Endian. Their color depth is 24 (or 32) and their format is ARGB (in GraphicConverter I have to check the "Interlaced" option to get the correct result).
For instance:
A file 1337x750 weighs 4011000 bytes which is 1337 x 750 x 4 (four 0-255 integers, one for each component - A, R, G, B in that order).

What should be the correct convert line in order to get it right?
This doesn't work: neither does this:

You have to specify the color channel depth, not the overall image depth. And you should also choose how to handle the transparency (e.g. by flattening over a background color) - as JPG can't store transparency.

Apart from that, I don't think that there's a raw ARGB format in ImageMagick (or is it?). But you can use one of the other raw 4-channel formats and rearrange the channels with some workarounds.
You could use "-color-matrix": Or you could separate the channels and change the order with image sequence operations, e.g. like that: (The handling of the alpha channel complicates matters in this case. I tested some other file formats and operations, but there was always some obstacle.. Maybe someone else knows a more simple commandline.)

I get this:

Did you also try the second commandline?

And: You probably have an old version of ImageMagick. (What exact version?)

shahar wrote:I get this:

Code: Select all

convert: unrecognized option `-color-matrix'.

On older versions of IM, use -recolor with a 3x3 matrix

I use ImageMagick-6.6.3-7 on linux which is a rather new version from what I gather.

I did try the other command and ended up with a completely black jpg file.
I will note though, that when using the rgba filter without the -color-matrix rearrangement I the correct picture with the exception that blue colors are interchanged with yellow.

Any ideas why -color-matrix is not recognized?

Well, I feel kinda stupid! revealed I was indeed using an old version of ImageMagick that I was not even aware was installed on the system I am using.
I work on some remote supercomputer which is not very well maintained.

The -color-matrix option worked perfectly! Thanks.