TYPO3 generates dark images

Since a security update of ImageMagick TYPO3 generates images which are really dark. The problem seems to be the colorspace setting. ImageMagick changed the default behaviour. Changing or adding sRGB as a value to the colorspace key in /typo3conf/LocalConfiguration.php fixes this issue!

'GFX' => array(
    (...)
    'colorspace' => 'sRGB',
    (...)
)

While you’re at it, make sure you have your jpg quality settings right… I find 80 to be an optimal value for the jpg_quality setting resulting in relatively crisp images while keeping the filesize low:

'GFX' => array(
    (...)
    'jpg_quality' => '80',
    (...)
)