[magick-users] MagickGetImageDepth performance issues

[duc.sequere.aut.de.via.decede at imagemagick.org]

> wand->image->depth

The image depth is problematic because do you want the depth the image
file reports or the actual depth which may differ.  For example, 4-bit
pixels may be stored in a 8-bit image file.  We suspect the best solution
may be to return the image->depth if the image is not tainted (no pixels
have been updated) and iterate over the pixels when the image is tainted.
The alternative is to have two different methods to return image depth:
reported and actual.  If you have a preference, let us know.  We'll get a
patch in ImageMagick-6.3.8-3 Beta in the next few days.