For people like me who like a quick reference, the filters are:FILTER_UNDEFINED => UndefinedFilterFILTER_POINT => PointFilterFILTER_BOX => BoxFilterFILTER_TRIANGLE => TriangleFilterFILTER_HERMITE => HermiteFilterFILTER_HANNING => HanningFilterFILTER_HAMMING => HammingFilterFILTER_BLACKMAN => BlackmanFilterFILTER_GAUSSIAN => GaussianFilterFILTER_QUADRATIC => QuadraticFilterFILTER_CUBIC => CubicFilterFILTER_CATROM => CatromFilterFILTER_MITCHELL => MitchellFilterFILTER_LANCZOS => LanczosFilterFILTER_BESSEL => BesselFilterFILTER_SINC => SincFilterRef: https://github.com/vitoc/gmagick/blob/master/gmagick_helpers.c