ImageGear PDF v25.2 - Updated
Reduce Method
Example 




ImageGear.Core Assembly > ImageGear.Processing Namespace > ImGearRasterProcessing Class : Reduce Method
Image to reduce bit depth.
Color space to reduce image to.
Channel depths to reduce image to.
Method to use for reducing bit depth.
Options to use for reduction, or set to null to use defaults.
Reduces bit depth of an image using the specified reduction method.
Syntax
'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.
Remarks
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
Example
// 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);
' 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)
See Also

Reference

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

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