ColorThresholdCommand Class

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public class ColorThresholdCommand : Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

'Declaration
 
Public Class ColorThresholdCommand 
   Inherits Leadtools.ImageProcessing.RasterCommand
   Implements Leadtools.ImageProcessing.IRasterCommand

'Usage
 
Dim instance As ColorThresholdCommand

public sealed class ColorThresholdCommand : Leadtools.ImageProcessing.IRasterCommand

function Leadtools.ImageProcessing.Color.ColorThresholdCommand()

public ref class ColorThresholdCommand : public Leadtools.ImageProcessing.RasterCommand, Leadtools.ImageProcessing.IRasterCommand

Every color space component may have a different range:

Color Component	Range for 8 bit per component.	Range for 16 bit per component.
RGB
R	0 ... 255	0 ... 65535
G	0 ... 255	0 ... 65535
B	0 ... 255	0 ... 65535
HSV
H	0 ... 360	0 ... 36000
S	0 ... 100	0 ... 10000
V	0 ... 255	0 ... 65535
HLS
H	0 ... 360	0 ... 36000
L	0 ... 255	0 ... 65535
S	0 ... 100	0 ... 10000
XYZ
X	0 ... 255	0 ... 65535
Y	0 ... 255	0 ... 65535
Z	0 ... 255	0 ... 65535
YCrCb
Y	0 ... 255	0 ... 65535
Cr	-128 ... 127	-32768 ... 32767
Cb	-128 ... 127	-32768 ... 32767
YUV
Y	0 ... 255	0 ... 65535
U	-112 ... 111	-28567 ... 28566
V	-138 ... 137	-35337 ... 35336
LAB
L	0 ... 100	0 ... 10000
A	-128 ... 127	-32768 ... 32767
B	-128 ... 127	-32768 ... 32767
CMY
C	0 ... 255	0 ... 65535
M	0 ... 255	0 ... 65535
Y	0 ... 255	0 ... 65535

This class works as follows:

The image is converted to the required color space.
For every pixel, the following operations are performed: Each component is compared with the MinimumRange and MaximumRange values of the appropriate ColorThresholdCommandComponent class.
- If it is inside the range, the component is considered to have "passed" the test.
- If it is outside the range, the component has been rejected". The ColorThresholdCommandFlags.BandReject flag inverts this by making "rejected" components "passed" and vice-versa.
If ColorThresholdCommandFlags.EffectChannel is set, the components are modified independently. If ColorThresholdCommandFlags.EffectAll has been set, the pixel is rejected by the test if any component is rejected. If the pixel/component is rejected, then:
- If ColorThresholdCommandFlags.SetToMinimum is set, the rejected pixel/component is set to 0.
- If ColorThresholdCommandFlags.SetToMaximum is set, the rejected pixel/component is set to 255.
- If ColorThresholdCommandFlags.SetToClamp is set, components less that MinimumRange go to 0 and components greater than MaximumRange go to 255. This would work only with the ColorThresholdCommandFlags.EffectChannel and ColorThresholdCommandFlags.BandBass flags.

This class works for 1, 2, 3, _ 8,16, 24, 32, 48 and 64-bit color images and can support regions for 24 and 48-bit images. If a 24 or 48-bit image has a region the effect will be applied on the region only.
One class is used for each color component. The order is considered to be the same as in the xxx Space name. For example, for RGB Space:
- Components[0] class is used for the Red component.
- Components[1] class is used for the Green component.
- Components[2] class is used for the Blue component.
This command does not support grayscale images.
This command does not support signed images.
This command does not support 1-bit bitonal images.

For more information, refer to Introduction to Image Processing With LEADTOOLS.
For more information, refer to Correcting Colors.

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Public Sub ColorThresholdCommandExample()
   Dim codecs As New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Master.jpg"))

   ' Prepare the command
   Dim components() As ColorThresholdCommandComponent
   ReDim components(2)
   components(0) = New ColorThresholdCommandComponent
   components(1) = New ColorThresholdCommandComponent
   components(2) = New ColorThresholdCommandComponent

   components(0).MinimumRange = 128
   components(0).MaximumRange = 255
   components(0).Flags = 0
   components(1).MinimumRange = 128
   components(1).MaximumRange = 255
   components(1).Flags = 0
   components(2).MinimumRange = 128
   components(2).MaximumRange = 255
   components(2).Flags = 0
   Dim command As ColorThresholdCommand = New ColorThresholdCommand(ColorThresholdCommandType.Rgb, components)
   'Apply color Threshold effect on the image.
   command.Run(leadImage)
   codecs.Save(leadImage, Path.Combine(LEAD_VARS.ImagesDir, "Result.jpg"), RasterImageFormat.Jpeg, 24)

End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

public void ColorThresholdCommandExample()
   {
      // Load an image
      RasterCodecs codecs = new RasterCodecs();
      codecs.ThrowExceptionsOnInvalidImages = true;

      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Master.jpg"));

      // Prepare the command
      ColorThresholdCommandComponent[] Components = new ColorThresholdCommandComponent[3];

      Components[0] = new ColorThresholdCommandComponent();
      Components[0].MinimumRange = 128;
      Components[0].MaximumRange = 255;
      Components[0].Flags        = 0;
      Components[1] = new ColorThresholdCommandComponent();
      Components[1].MinimumRange = 128;
      Components[1].MaximumRange = 255;
      Components[1].Flags        = 0;
      Components[2] = new ColorThresholdCommandComponent();
      Components[2].MinimumRange = 128;
      Components[2].MaximumRange = 255;
      Components[2].Flags        = 0;

      ColorThresholdCommand command = new ColorThresholdCommand(ColorThresholdCommandType.Rgb, Components);
      //Apply color Threshold effect on the image.
      command.Run(image);
      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Result.jpg"), RasterImageFormat.Jpeg, 24);

   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

[TestMethod]
public async Task ColorThresholdCommandExample()
{
   // Load an image
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   // Load the image
   string srcFileName = @"Assets\Image1.cmp";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   // Prepare the command
   ColorThresholdCommandComponent[] Components = new ColorThresholdCommandComponent[3];

   Components[0] = new ColorThresholdCommandComponent();
   Components[0].MinimumRange = 128;
   Components[0].MaximumRange = 255;
   Components[0].Flags        = 0;
   Components[1] = new ColorThresholdCommandComponent();
   Components[1].MinimumRange = 128;
   Components[1].MaximumRange = 255;
   Components[1].Flags        = 0;
   Components[2] = new ColorThresholdCommandComponent();
   Components[2].MinimumRange = 128;
   Components[2].MaximumRange = 255;
   Components[2].Flags        = 0;

   ColorThresholdCommand command = new ColorThresholdCommand(ColorThresholdCommandType.Rgb, Components);
   //Apply color Threshold effect on the image.
   command.Run(image);

   string destFileName = @"result.jpg";
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.Jpeg, 0);
}

public void ColorThresholdCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   ColorThresholdCommandComponent[] Components = new ColorThresholdCommandComponent[3];
   Components[0] = new ColorThresholdCommandComponent();
   Components[0].MinimumRange = 128;
   Components[0].MaximumRange = 255;
   Components[0].Flags        = 0;
   Components[1] = new ColorThresholdCommandComponent();
   Components[1].MinimumRange = 128;
   Components[1].MaximumRange = 255;
   Components[1].Flags        = 0;
   Components[2] = new ColorThresholdCommandComponent();
   Components[2].MinimumRange = 128;
   Components[2].MaximumRange = 255;
   Components[2].Flags        = 0;

   ColorThresholdCommand command = new ColorThresholdCommand(ColorThresholdCommandType.Rgb, Components);
   //Apply color Threshold effect on the image.
   command.Run(image);

   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24);
   image.Dispose();
}

Public Sub ColorThresholdCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim Components As ColorThresholdCommandComponent() = New ColorThresholdCommandComponent(2){}
   Components(0) = New ColorThresholdCommandComponent()
   Components(0).MinimumRange = 128
   Components(0).MaximumRange = 255
   Components(0).Flags = 0
   Components(1) = New ColorThresholdCommandComponent()
   Components(1).MinimumRange = 128
   Components(1).MaximumRange = 255
   Components(1).Flags = 0
   Components(2) = New ColorThresholdCommandComponent()
   Components(2).MinimumRange = 128
   Components(2).MaximumRange = 255
   Components(2).Flags = 0

   Dim command As ColorThresholdCommand = New ColorThresholdCommand(ColorThresholdCommandType.Rgb, Components)
   'Apply color Threshold effect on the image.
   command.Run(image)

   ' Save result image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24)
   image.Dispose()
End Sub

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference