_output_gamma->SetIncrement (0.1);
_input_gamma->Bind (wxEVT_COMMAND_SPINCTRLDOUBLE_UPDATED, boost::bind (&ColourConversionEditor::changed, this));
_output_gamma->SetIncrement (0.1);
_input_gamma->Bind (wxEVT_COMMAND_SPINCTRLDOUBLE_UPDATED, boost::bind (&ColourConversionEditor::changed, this));