List of ImageMagick types that should never be treated as images.
This should be a list of symbols, each of which should be one of
the ImageMagick types listed by `imagemagick-types'. The listed
image types are not registered by `imagemagick-register-types'.
If the value is t, inhibit the use of ImageMagick for images.
If you change this without using customize, you must call
If Emacs is compiled without ImageMagick support, this variable has no effect.