{namespace i=TYPO3\CMS\Install\ViewHelpers}
This verifies that your ImageMagick installation is able to read the default formats jpg, gif, png, tif, pdf and ai. The tool identify is used to read the pixeldimensions of non-web formats and 'convert' is used to read the image and convert it to jpg.
jpg
gif
png
tif
pdf
ai
identify
Test-Image by Rotkaeppchen68 (in de.wikipedia) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons