Some instalation problems

ProblemSample errorPossible cause
ImageMagick will run in command line but not in the php code. sh: convert: command not found The path to the ImageMagick programs can not be found.

If you are just using convert you will need to use something like user/local/bin/convert

You can use the code here to find the path you need.
" " Set PATH environment variable in the PHP or tell your administartors that the PHP command path is not set right for IM and GS. If the web server has the right path PHP usally inherits it and then it can find things properly!
Text will not be added to an image. Error: /invalidfont in /findfont

GPL Ghostscript 8.60: Unrecoverable error, exit code 1
Fault with the font setup in Ghostscript
You can modify some images but not others. Error: None The image you are working with may not be supported

Try running the code below ( the image should have an 'r' next to the extension to read and a 'w' to be able to write ).

system ("convert -list Format");