ExtractObjectsCommand Class

Summary

Extracts the connected groups of pixels from a bitmap using various options.

Syntax

C++

public class ExtractObjectsCommand : RasterCommand

Public Class ExtractObjectsCommand 
   Inherits RasterCommand

public: 
   ref class ExtractObjectsCommand : RasterCommand

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
 
public void ExtractObjectsCommandExample() 
{ 
   using (RasterCodecs codecs = new RasterCodecs()) 
   // Load the original image 
   using (RasterImage inputImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "demoicr2.tif"))) 
   { 
      // Setup the extraction options 
      ExtractObjectsCommand command = new ExtractObjectsCommand() 
      { 
         DetectChildren = true, 
         EightConnectivity = true, 
         Outline = true 
      }; 
 
      // Extract the objects 
      command.Run(inputImage); 
 
      using (ExObjData data = command.Data) 
      { 
         // Log the number of objects from the first list 
         ExObjObjectList objects = data[0].Objects; 
         Console.WriteLine($"Number of objects (before filtering): {objects.Count}"); 
 
         // Log the number of points around the first object (braces for scope) 
         { 
            int count = 0; 
            foreach (ExObjOutlinePoint point in objects.First().Outline) 
               count++; 
            Console.WriteLine($"First object's outline length: {count}"); 
         } 
 
         // Setup the filter options 
         ExObjFilterOptions filterOptions = new ExObjFilterOptions() 
         { 
            LargeObjectThreshold = -1, // No upper limit on size 
            SmallObjectThreshold = 10 // Remove objects smaller than 10x10 pixels 
         }; 
 
         // Filter the objects 
         data.FilterList(objects, filterOptions); 
 
         // Log the number of objects again 
         Console.WriteLine($"Number of objects (after filtering): {objects.Count}"); 
 
         // Setup the content bound options 
         ExObjContentBound contentBound = new ExObjContentBound(new LeadRect(192, 260, 323, 146)); 
         ExObjContentBoundOptions contentBoundOptions = new ExObjContentBoundOptions() 
         { 
            ObjectsOfInterest = null // Pass null to use every object in data 
         }; 
 
         // Calculate the content bounds 
         data.CalculateContentBound(new ExObjContentBound[] { contentBound }, contentBoundOptions); 
 
         // Setup the region options 
         ExObjRegionOptions regionOptions = new ExObjRegionOptions() 
         { 
            Horizontal = true 
         }; 
 
         // Calculate each object's region 
         data.CalculateRegion(objects, regionOptions); 
 
         // Create an output image 
         using (RasterImage outputImage = RasterImage.Create(inputImage.Width, inputImage.Height, 24, inputImage.XResolution, RasterColor.White)) 
         { 
            // Fill the output image with white 
            new FillCommand(RasterColor.White).Run(outputImage); 
 
            // Draw the content bound rects for the first word. Red for the input, green for the output. 
            outputImage.AddRectangleToRegion(null, contentBound.Input, RasterRegionCombineMode.Set); 
            new FillCommand(new RasterColor(255, 0, 0)).Run(outputImage); 
            outputImage.AddRectangleToRegion(null, contentBound.Content, RasterRegionCombineMode.Set); 
            new FillCommand(new RasterColor(0, 255, 0)).Run(outputImage); 
 
            // Populate the output image with each object's region 
            foreach (ExObjObject @object in objects) 
               foreach (ExObjSegment segment in @object.RegionHorizontal) 
               { 
                  // Update the region to the current segment 
                  outputImage.AddRectangleToRegion(null, segment.Bounds, RasterRegionCombineMode.Set); 
 
                  // Fill the region with black 
                  new FillCommand(RasterColor.Black).Run(outputImage); 
               } 
 
            // Clear the output image's region 
            outputImage.MakeRegionEmpty(); 
 
            // Save the output image 
            codecs.Save(outputImage, Path.Combine(LEAD_VARS.ImagesDir, "ExtractObjects.png"), RasterImageFormat.Png, 0); 
         } 
      } 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Core 
 
Public Sub ExtractObjectsCommandExample() 
   Using codecs As New RasterCodecs() 
      ' Load the original image 
      Using inputImage As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "demoicr2.tif")) 
         ' Setup the extraction options 
         Dim command As New ExtractObjectsCommand() With { 
            .DetectChildren = True, 
            .EightConnectivity = True, 
            .Outline = True 
         } 
 
         ' Extract the objects 
         command.Run(inputImage) 
 
         Using data As ExObjData = command.Data 
            ' Log the number of objects from the first list 
            Dim objects As ExObjObjectList = data(0).Objects 
            Console.WriteLine($"Number of objects (before filtering): {objects.Count}") 
 
            ' Log the number of points around the first object 
            Dim count As Integer = 0 
            For Each point As ExObjOutlinePoint In objects.First().Outline 
               count += 1 
            Next 
            Console.WriteLine($"First object's outline length: {count}") 
 
            ' Setup the filter options 
            Dim filterOptions As New ExObjFilterOptions() With { 
               .LargeObjectThreshold = -1, ' No upper limit on size 
               .SmallObjectThreshold = 10 ' Remove objects smaller than 10x10 pixels 
            } 
 
            ' Filter the objects 
            data.FilterList(objects, filterOptions) 
 
            ' Log the number of objects again 
            Console.WriteLine($"Number of objects (after filtering): {objects.Count}") 
 
            ' Setup the content bound options 
            Dim contentBound As New ExObjContentBound(New LeadRect(192, 260, 323, 146)) 
            Dim contentBoundOptions As New ExObjContentBoundOptions() With { 
               .ObjectsOfInterest = Nothing ' Pass Nothing to use every object in data 
            } 
 
            ' Calculate the content bounds 
            data.CalculateContentBound(New ExObjContentBound() {contentBound}, contentBoundOptions) 
 
            ' Setup the region options 
            Dim regionOptions As New ExObjRegionOptions() With { 
               .Horizontal = True 
            } 
 
            ' Calculate each object's region 
            data.CalculateRegion(objects, regionOptions) 
 
            ' Create an output image 
            Using outputImage As RasterImage = RasterImage.Create(inputImage.Width, inputImage.Height, 24, inputImage.XResolution, RasterColor.White) 
               ' Fill the output image with white 
               Call New FillCommand(RasterColor.White).Run(outputImage) 
 
               ' Draw the content bound rects for the first word. Red for the input, green for the output. 
               outputImage.AddRectangleToRegion(Nothing, contentBound.Input, RasterRegionCombineMode.[Set]) 
               Call New FillCommand(New RasterColor(255, 0, 0)).Run(outputImage) 
               outputImage.AddRectangleToRegion(Nothing, contentBound.Content, RasterRegionCombineMode.[Set]) 
               Call New FillCommand(New RasterColor(0, 255, 0)).Run(outputImage) 
 
               ' Populate the output image with each object's region 
               For Each [object] As ExObjObject In objects 
                  For Each segment As ExObjSegment In [object].RegionHorizontal 
                     ' Update the region to the current segment 
                     outputImage.AddRectangleToRegion(Nothing, segment.Bounds, RasterRegionCombineMode.[Set]) 
 
                     ' Fill the region with black 
                     Call New FillCommand(RasterColor.Black).Run(outputImage) 
                  Next 
               Next 
 
               ' Clear the output image's region 
               outputImage.MakeRegionEmpty() 
 
               ' Save the output image 
               codecs.Save(outputImage, Path.Combine(LEAD_VARS.ImagesDir, "ExtractObjects.png"), RasterImageFormat.Png, 0) 
            End Using 
         End Using 
      End Using 
   End Using 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

Reference

ExtractObjectsCommand Members

Leadtools.ImageProcessing.Core Namespace

Download our FREE evaluation

Help Version 21.0.2021.7.2

Leadtools.ImageProcessing.Core Assembly

Introduction

Getting Started

Namespaces

Leadtools.ImageProcessing.Core Namespace

Assemblies