The MagickWand interface is a new high-level C API interface to ImageMagick core methods. We discourage the use of the core methods and encourage the use of this API instead. Post MagickWand questions, bug reports, and suggestions to this forum.
contains a program submitted by el_supremo that seems to critically depend on the capability of SetImageOpacity to set an arbitrary image opacity (other than completely opaque).
How can one change this program to achieve the same effect using the MagickWand API exclusively?
We'll add a MagickSetImageOpacity() method to the MagickWand API in the next release. For now you need to set the opacity yourself with a PixelWand iterator.