tif > png bug?

[NickKuh]

I have ImageMagick installed on my local computer (Mac OS X) and a client's server for a project I'm developing.

I believe the versions of ImageMagick on both servers are identical -

Local OS X version:

Version: ImageMagick 6.3.5 08/24/07 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2007 ImageMagick Studio LLC

Client webserver version:

Version: ImageMagick 6.3.5 09/03/07 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2007 ImageMagick Studio LLC

However they are producing different results for the same file conversion. It's a tif to png conversion and I've posted the 3 files here:

http://www.editioninteractive.net/imagemagick/

ImageMagick is performing a good conversion via my OSX installation with no errors. On the client server the result is an inverted colour image and the following errors:

convert: unknown field with tag 700 (0x2bc) ignored. `gorilla.tif'.
convert: unknown field with tag 34665 (0x8769) ignored. `gorilla.tif'

Any help appreciated.

Nick

[magick]

An easy fix to the problem, assuming you have the LCMS delegate library as part of the ImageMagick build, would be to use color profiles to perform proper conversion from the CMYK to RGB colorspace. Try this:

• convert gorilla.tif -profile USWebCoatedSWOP.icc -profile sRGB.icm gorilla.png

[NickKuh]

I tried you suggestion and got the following:

convert: unknown field with tag 700 (0x2bc) ignored. `gorilla.tif'.
convert: unknown field with tag 34665 (0x8769) ignored. `gorilla.tif'.
convert: unable to open file `USWebCoatedSWOP.icc': No such file or directory.
convert: unable to open file `sRGB.icm': No such file or directory

How do I add the 'LCMS delegate library'?

Many thanks

Nick

[magick]

You will need to track down the profiles with Google. You can tell if the LCMS delegate library was built into your version of ImageMagick with this command:

• identify -list configure

Look for the DELEGATES tag and see if it includes lcms. On our system we have

• DELEGATES bzlib fontconfig fpx freetype gvc jbig jpeg jp2 lcms openexr png rsvg tiff wmf x11 xml wmf zlib

[NickKuh]

Ok, I ran the identify -list configure command on both my local version and the server version. It appears that my local version has a load more delegates and options installed.

My local version was installed using Darwin/Mac Ports. I wonder if the comparison between these 2 might shed some more light on what I need to change to the config of the web server version to get the CMYK > RGB image conversion working ok?

Here's a screengrab - local results on the left and server results on the right:



Even if I do find the profiles you've mentioned that would mean implementing a number of changes to my working system as users are able to upload a range of image types - some CMYK and some RGB and would require testing for image profiles rather than letting ImageMagick automate it as it does perfectly already with my local installation.

Thanks for any further help!

Nick