The only options used by the ImGearRasterProcessing.Reduce method are the ones which correspond to the type of reduction as specified by the reductionMethod parameter of the ImGearRasterProcessing.Reduce method.
// Reduce the bit depth of an image to 4 bit
// Create reduction options object and setup a few values for a 16 color 4-bit reduction.
ImGearReductionOptions igReductionOptions = new ImGearReductionOptions();
igReductionOptions.Octree.MaxColors = 16;
igReductionOptions.Octree.FastRemap = false;
igReductionOptions.Octree.ErrorDiffusion = true;
//Apply the reduction using Octree to get a 4-bit index image.
ImGearRasterProcessing.Reduce(igRasterPage, new ImGearColorSpace(ImGearColorSpaceIDs.I),
newint[] { 4 }, ImGearReductionMethods.OCTREE, igReductionOptions);
' Reduce the bit depth of an image to 4 bit
' Create reduction options object and setup a few values for a 16 color 4-bit reduction.
Dim igReductionOptions AsNew ImGearReductionOptions()
igReductionOptions.Octree.MaxColors = 16
igReductionOptions.Octree.FastRemap = False
igReductionOptions.Octree.ErrorDiffusion = True'Apply the reduction using Octree to get a 4-bit index image.
ImGearRasterProcessing.Reduce(igRasterPage, New ImGearColorSpace(ImGearColorSpaceIDs.I), NewInteger() {4}, _
ImGearReductionMethods.OCTREE, igReductionOptions)