SpatialFilterCommand Class | Leadtools.ImageProcessing.Effects

Summary

Imposes a spatial filter on an image. This command is available in the Document/Medical Toolkits.

Syntax

C#

VB

Objective-C

C++

Java

public class SpatialFilterCommand : RasterCommand

Public Class SpatialFilterCommand  
   Inherits RasterCommand

@interface LTSpatialFilterCommand : LTRasterCommand

public class SpatialFilterCommand extends RasterCommand

public ref class SpatialFilterCommand : public RasterCommand

Remarks

A spatial filter recomputes the brightness of each pixel in an image by using a weighted averaging technique that considers the surrounding pixels. Spatial filters are used for operations such as sharpening an image or detecting edges within the image.
The SpatialFilterCommand works best with 24-bit, 16-bit, or grayscale images. If the image uses a color palette, this command matches the new brightness value of each pixel to the nearest color in the existing palette.
This command 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.
It is beyond the scope of this documentation to explain how applying various weighting factors affects an image. If you specify your own filter, you should refer to a textbook on image processing. For example, Digital Image Processing: Principles and Applications, by Gregory A. Baxes.
This command does not support 32-bit grayscale images.

For more information, refer to Detecting and Enhancing Edges and Lines. For more information, refer to List of Spatial Filters.

Example

Run the SpatialFilterCommand on an image and applies a Prewitt edge detection filter.

C#

VB

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing.Effects; 
 
public void SpatialFilterCommandExample() 
{ 
   // Load an image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
 
   RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "ImageProcessingDemo\\NaturalFruits.jpg")); 
 
   // Prepare the command 
   SpatialFilterCommand command = new SpatialFilterCommand(SpatialFilterCommandPredefined.PrewittHorizontal); 
   //Apply a Prewitt edge detection filter. 
   command.Run(image); 
 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing.Effects 
 
Public Sub SpatialFilterCommandExample() 
   Dim codecs As New RasterCodecs() 
   codecs.ThrowExceptionsOnInvalidImages = True 
 
   Dim leadImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "ImageProcessingDemo\\NaturalFruits.jpg")) 
 
   ' Prepare the command 
   Dim command As SpatialFilterCommand = New SpatialFilterCommand(SpatialFilterCommandPredefined.PrewittHorizontal) 
   'Apply a Prewitt edge detection filter. 
 
   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

c#[Silverlight C# Example] 
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing.Effects; 
using Leadtools.Examples; 
 
public void SpatialFilterCommandExample(RasterImage image, Stream outStream) 
{ 
   // Prepare the command 
   SpatialFilterCommand command = new SpatialFilterCommand(SpatialFilterCommandPredefined.PrewittHorizontal); 
   //Apply a Prewitt edge detection filter. 
   // Save result image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24); 
   image.Dispose(); 
} 
vb[Silverlight VB Example] 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing.Effects 
 
Public Sub SpatialFilterCommandExample(ByVal image As RasterImage, ByVal outStream As Stream) 
   ' Prepare the command 
   Dim command As SpatialFilterCommand = New SpatialFilterCommand(SpatialFilterCommandPredefined.PrewittHorizontal) 
   'Apply a Prewitt edge detection filter. 
   ' Save result image 
   Dim codecs As RasterCodecs = New RasterCodecs() 
   codecs.Save(image, outStream, RasterImageFormat.Jpeg, 24) 
   image.Dispose() 
End Sub