CorrelationListCommand Class

Summary

Compares the images in a list with all the areas of the same dimensions in an image and finds those portions that match according to the measure of correlation. This method is only available in the Document/Medical toolkits.

Syntax

Objective-C

C++/CLI

Java

Python

public class CorrelationListCommand : RasterCommand

@interface LTCorrelationListCommand : LTRasterCommand

public class CorrelationListCommand 
    extends RasterCommand

public ref class CorrelationListCommand : public RasterCommand

class CorrelationListCommand(RasterCommand):

Remarks

This method compares the images in a list with all the areas of the same dimensions in image and finds those areas that match according to the measure of correlation.
All the list images must have the same dimensions. The dimensions must be less than or equal to the image dimensions.
Correlation is a measure of association (resemblance) between two images. It varies from 0 (zero resemblance) to 100 (perfect resemblance).
This method updates the Points parameter with the point of origin for those areas of the image where the resemblance with an image in the list is greater than the value of Threshold. It also updates ListIndex with the index of that image.
For example:
1. Select images of the objects for which you want to look and put them in a list For example:
2. Select an image that contains the objects for which you are searching. For example:
3. Set XStep = 1, YStep = 1 and Threshold = 90 then run the command
4. Points array will be updated with the point of origin (top-left) for each area of the image where the correlation with an image in the list is greater than the correlation Threshold. The height and width of the rectangles are the same as for list images.
5. The result
This method 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.
If the image has a region, this method works only on the region. If the image does not have a region, this method works on the entire image.
This method does not support signed data images.
This command does not support 32-bit grayscale images.

Example

Run the CorrelationListCommand on an image.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
 
public void CorrelationListCommandExample() 
{ 
   // Load an image 
   RasterCodecs codecs = new RasterCodecs(); 
   codecs.ThrowExceptionsOnInvalidImages = true; 
 
   RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "clean.tif")); 
 
   CorrelationListCommand command = new CorrelationListCommand(); 
   CopyRectangleCommand copyRectangle = new CopyRectangleCommand(); 
 
   LeadRect rc_cor = new LeadRect(458, 591, 21, 28); 
   copyRectangle.Rectangle = rc_cor; 
   copyRectangle.Run(image); 
   command.CorrelationImage = copyRectangle.DestinationImage.Clone(); 
 
   rc_cor = new LeadRect(507, 591, 21, 28); 
   copyRectangle.Rectangle = rc_cor; 
   copyRectangle.Run(image); 
   command.CorrelationImage.AddPage(copyRectangle.DestinationImage.Clone()); 
 
   command.Points = new LeadPoint[30]; 
   command.ListIndex = new int[30]; 
   command.Threshold = 90; 
   command.XStep = 1; 
   command.YStep = 1; 
   command.Run(image); 
 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}