DCMTK

Some DCMTK modules are free of warnings, others are not.

From "man gcc":

-Wconversion
           Warn for implicit conversions that may alter a value. This includes conversions between real and integer, like "abs (x)" when "x" is "double";
           conversions between signed and unsigned, like "unsigned ui = -1"; and conversions to smaller types, like "sqrtf (M_PI)". Do not warn for explicit
           casts like "abs ((int) x)" and "ui = (unsigned) -1", or if the value is not changed by the conversion like in "abs (2.0)".  Warnings about
           conversions between signed and unsigned integers can be disabled by using -Wno-sign-conversion.
           For C++, also warn for confusing overload resolution for user-defined conversions; and conversions that never use a type conversion operator:
           conversions to "void", the same type, a base class or a reference to them. Warnings about conversions between signed and unsigned integers are
           disabled by default in C++ unless -Wsign-conversion is explicitly enabled.