SpatialFilterCommand Class | Leadtools.ImageProcessing.Effects

Summary

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

Syntax

C#

Objective-C

C++/CLI

Java

Python

public class SpatialFilterCommand : RasterCommand

@interface LTSpatialFilterCommand : LTRasterCommand

public class SpatialFilterCommand 
    extends RasterCommand

public ref class SpatialFilterCommand : public RasterCommand

class SpatialFilterCommand(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#

Java

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:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.File; 
import java.io.IOException; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.assertTrue; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.imageprocessing.effects.*; 
 
 
public void spatialFilterCommandExample() { 
   String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
 
   // Load an image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.setThrowExceptionsOnInvalidImages(true); 
 
   RasterImage image = codecs.load(combine(LEAD_VARS_IMAGES_DIR, "NaturalFruits.jpg")); 
 
   // Prepare the command 
   SpatialFilterCommand command1 = new SpatialFilterCommand(SpatialFilterCommandPredefined.EMBOSS_SOUTH); 
   int[] data = command1.getMatrix(); 
   SpatialFilterCommand command = new SpatialFilterCommand(); 
   command.setDivisor(command1.getDivisor()); 
   command.setBias(command1.getBias()); 
   command.setMatrix(data); 
   System.out.printf("Array Dimension is : %s", command.getDimension()); 
   System.out.println(" "); 
 
   // Apply the filter. 
   int change = command.run(image); 
   assertTrue(change != RasterImageChangedFlags.NONE); 
 
   // Save the image 
   String outputFileName = combine(LEAD_VARS_IMAGES_DIR, "NaturalFruits1.jpg"); 
   codecs.save(image, outputFileName, RasterImageFormat.JPEG, 0); 
   System.out.println("Command run, file saved to " + outputFileName); 
}