'Declaration
Public Function TwainGetContrast() As Integer
public int TwainGetContrast()
public function TwainGetContrast(): Integer;
public function TwainGetContrast() : int;
public: int TwainGetContrast();
public: int TwainGetContrast();
Return Value
If Success: The TWAIN standard *says* that the range for this cap is -1000 ... +1000. If fail,
Returns -99999 -> Use TwainGetLastResultCode() and TwainGetLastConditionCode() methods for
diagnosing the error.