Reduce Method

public static void Reduce( 
   ImGearRasterPage page,
   ImGearColorSpace colorSpace,
   int[] channelDepths,
   ImGearReductionMethods reductionMethod,
   ImGearReductionOptions options
)

public: static void Reduce( 
   ImGearRasterPage* page,
   ImGearColorSpace colorSpace,
   int[]* channelDepths,
   ImGearReductionMethods reductionMethod,
   ImGearReductionOptions* options
)

public:
static void Reduce( 
   ImGearRasterPage^ page,
   ImGearColorSpace colorSpace,
   array<int>^ channelDepths,
   ImGearReductionMethods reductionMethod,
   ImGearReductionOptions^ options
)

'Declaration
 
Public Shared Sub Reduce( _
   ByVal page As ImGearRasterPage, _
   ByVal colorSpace As ImGearColorSpace, _
   ByVal channelDepths() As Integer, _
   ByVal reductionMethod As ImGearReductionMethods, _
   ByVal options As ImGearReductionOptions _
)

'Usage
 
Dim page As ImGearRasterPage
Dim colorSpace As ImGearColorSpace
Dim channelDepths() As Integer
Dim reductionMethod As ImGearReductionMethods
Dim options As ImGearReductionOptions
 
ImGearRasterProcessing.Reduce(page, colorSpace, channelDepths, reductionMethod, options)

Parameters

page: Image to reduce bit depth.
colorSpace: Color space to reduce image to.
channelDepths: Channel depths to reduce image to.
reductionMethod: Method to use for reducing bit depth.
options: Options to use for reduction, or set to null to use defaults.

All methods except for ImGearReductionMethods.SCALE change the color space of the image to Indexed. ImGearReductionMethods.SCALE does not change the image's color space, but only scales the channel depths. Different reduction methods have their own options, which can be set using the options parameter.

For more information about a particular method, see its options. The following reduction methods are available in ImGearReductionMethods:

Method	Input color spaces and bit depths	Output color spaces and bit depths	Options
BAYER	RGB (24)Grayscale (8)Indexed (>1)	Indexed (1 or 4)	ImGearBayerReductionOptions
BITONAL	RGB (24)Grayscale (8)Indexed (>1)	Indexed (1)	ImGearBitonalReductionOptions
DIFFUSE	RGB (24)Grayscale (8)Indexed (>1)	Indexed (1 or 4)	ImGearDiffuseReductionOptions
HALFTONE	RGB (24)Grayscale (8)Indexed (>1)	Indexed (1)	ImGearHalftoneReductionOptions
MEDIAN	RGB (24)Grayscale (8)	Indexed (8)	ImGearMedianCutReductionOptions
OCTREE	RGB (24)Grayscale (8)	Indexed (4 or 8)	ImGearOctreeReductionOptions
POPULARITY	RGB (24)Grayscale (8)	Indexed (8)	ImGearPopularityReductionOptions
SCALE	Any color space except Indexed	Same color space as input	ImGearScaleReductionOptions

C#

// 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),
    new int[] { 4 }, ImGearReductionMethods.OCTREE, igReductionOptions);

Visual Basic

' 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 As 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), New Integer() {4}, _
 ImGearReductionMethods.OCTREE, igReductionOptions)

Reference

ImGearRasterProcessing Class
ImGearRasterProcessing Members
ImGearRasterPage Class
ImGearColorSpace Structure
ImGearReductionOptions Class
ImGearReductionMethods Enumeration