$ diff  ../../image_science-1.1.3/lib/image_science.rb image_science.rb
110,111c110,112
<         VALUE klass = fif ? self         : CLASS_OF(self);
<         VALUE type  = fif ? INT2FIX(fif) : rb_iv_get(self, "@file_type");
---
>         unsigned int self_type = rb_type(self);
>         VALUE klass = (self_type == T_CLASS) ? self         : CLASS_OF(self);
>         VALUE type  = (self_type == T_CLASS) ? INT2FIX(fif) : rb_iv_get(self, "@file_type");