DynamicBinaryCommand Class

Converts an image into a black and white image without changing its bits per pixel by using a local threshold value for each pixel of the image. This function is useful for pre-processing images for the purpose of improving barcode recognition results.

Object Model

Syntax

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

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

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

'Usage
 
Dim instance As DynamicBinaryCommand

public sealed class DynamicBinaryCommand : Leadtools.ImageProcessing.IRasterCommand

function Leadtools.ImageProcessing.Color.DynamicBinaryCommand()

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

Remarks

This class converts an image into a black and white image without changing its bits per pixel.
Each pixel is compared to a dynamically-calculated threshold. If the intensity of the pixel is higher (that is, the pixel is brighter) than the dynamic threshold, the pixel will be set to white. If the intensity of the pixel is lower (that is, the pixel is darker) than the dynamic threshold, the pixel will be set to black.
Here are some hints on using this class:
Increasing the LocalContrast property increases the number of pixels that use the global threshold. This tends to preserve the general aspect of the image and reduces the improvement in the areas with many details. Reducing the LocalContrast property, increases the contrast in areas with many details.
Increasing the Dimension property increases the area used for local contrast. This makes the color changes smoother.
This class is good as a prerequisite for converting scanned images to 1-bit, because it uses one threshold for background and another for text.
This class supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.
This class does not support signed data images.
This command does not support 32-bit grayscale images.

Use the AutoBinaryCommand when you simply want to apply binary segmentation to the bitmap using an automatically calculated threshold based on a two-peak method of statistical analysis on its histogram. Use the DynamicBinaryCommand to convert an image into a black and white image without changing its bits per pixel. Use the AutoBinarizeCommand if you want:

Automatic pre-processing
Pre-processing to include background elimination
Pre-processing to include color leveling
To perform automatic, percentile or median thresholding
To manually specify a threshold value

For more information, refer to Introduction to Image Processing With LEADTOOLS.
For more information, refer to Changing Brightness and Contrast.
For more information, refer to Removing Noise.

Example

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

Public Sub DynamicBinaryCommandExample()
   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 command As DynamicBinaryCommand = New DynamicBinaryCommand
   command.Dimension = 8
   command.LocalContrast = 16
   ' convert it into a black and white image without changing its bits per pixel.
   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 DynamicBinaryCommandExample()
   {
      // Load an image
      RasterCodecs codecs = new RasterCodecs();
      codecs.ThrowExceptionsOnInvalidImages = true;

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

      // Prepare the command
      DynamicBinaryCommand command = new DynamicBinaryCommand();
      command.Dimension     = 8;
      command.LocalContrast = 16;
      // convert it into a black and white image without changing its bits per pixel.
      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 DynamicBinaryCommandExample()
{
   // 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
   DynamicBinaryCommand command = new DynamicBinaryCommand();
   command.Dimension     = 8;
   command.LocalContrast = 16;
   // convert it into a black and white image without changing its bits per pixel.
   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 DynamicBinaryCommandExample(RasterImage image, Stream outStream)
{
   // Prepare the command
   DynamicBinaryCommand command = new DynamicBinaryCommand();
   command.Dimension     = 8;
   command.LocalContrast = 16;
   // convert it into a black and white image without changing its bits per pixel.
   command.Run(image);
   // Save result image
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24);
   image.Dispose();
}

Public Sub DynamicBinaryCommandExample(ByVal image As RasterImage, ByVal outStream As Stream)
   ' Prepare the command
   Dim command As DynamicBinaryCommand = New DynamicBinaryCommand()
   command.Dimension = 8
   command.LocalContrast = 16
   ' convert it into a black and white image without changing its bits per pixel.
   command.Run(image)
   ' Save result image
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24)
   image.Dispose()
End Sub

Requirements

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