Warning: This function is
currently not documented; only the argument list is
available.
Warning: This function is
EXPERIMENTAL. The behaviour of this function, the
name of this function, and anything else documented about this
function may change without notice in a future release of PHP.
Use this function at your own risk.
Compares an image to a reconstructed image and returns the specified distortion
metric.
Return Values
Returns the distortion metric used on the image (or the best guess
thereof). Throws an exception on error.