If you are using Typo3 you should install the following expansion which uses the GD2 library instead of ImageMagick for some image operations. Since it is embedded directly in PHP this one is faster. ImageMagick may cause problems due to deactivated and safety-critical functions.

The expansion for Typo3 can be found directly at:

http://typo3.org/documentation/document-library/extension-manuals/jb_gd_resize/current/