HasRegion Property

Summary

Determines whether this RasterImage has a region.

Syntax

Objective-C

C++

Java

public bool HasRegion { get; }

Public ReadOnly Property HasRegion As Boolean

@property (nonatomic, assign, readonly) BOOL hasRegion

public boolean hasRegion()

public: 
property bool HasRegion { 
   bool get(); 
}

Property Value

true if this RasterImage has a region; false, otherwise.

Remarks

When an image has a region, the LEADTOOLS methods that modify the pixel values (for example PosterizeCommand) act on the region, rather than the whole image. In addition, the LEADTOOLS methods that flip, reverse, rotate, shear, or resize an image also transform the region to match the image. For example, if you were to shear the image that had a rectangular region, the region would become a parallelogram.

To remove an image region, use MakeRegionEmpty.

For more information, refer to Working with the Existing Region.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Dicom; 
using Leadtools.Drawing; 
using Leadtools.Controls; 
using Leadtools.Svg; 
 
 
public void RegionExample() 
{ 
	RasterCodecs codecs = new RasterCodecs(); 
 
	string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
	string destFileName1 = Path.Combine(LEAD_VARS.ImagesDir, "Image1_InvertRegion.bmp"); 
	string destFileName2 = Path.Combine(LEAD_VARS.ImagesDir, "Image1_InvertNoRegion.bmp"); 
 
	// Load the image 
	RasterImage image = codecs.Load(srcFileName); 
 
	// The image should have no region 
	Console.WriteLine("After loading, HasRegion = {0}", image.HasRegion); 
	Assert.IsTrue(!image.HasRegion); 
 
	// Add a region to the image 
	LeadRect rc = new LeadRect(0, 0, image.Width / 4, image.Height / 4); 
	image.AddEllipseToRegion(null, rc, RasterRegionCombineMode.Set); 
 
	// The image should have a region now 
	Console.WriteLine("After AddEllipseToRegion, HasRegion = {0}", image.HasRegion); 
	Assert.IsTrue(image.HasRegion); 
 
	// Invert this image and save it to a file 
	InvertCommand command = new InvertCommand(); 
	command.Run(image); 
	codecs.Save(image, destFileName1, RasterImageFormat.Bmp, 24); 
 
	// Get rid of the region 
	image.MakeRegionEmpty(); 
 
	// The image should not have a region now 
	Console.WriteLine("After MakeRegionEmpty, HasRegion = {0}", image.HasRegion); 
	Assert.IsTrue(!image.HasRegion); 
 
	// Invert again and save it 
	command.Run(image); 
	codecs.Save(image, destFileName2, RasterImageFormat.Bmp, 24); 
 
	image.Dispose(); 
	codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Core 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.Controls 
Imports Leadtools.Dicom 
Imports Leadtools.Drawing 
Imports Leadtools.Svg 
 
Public Sub RegionExample() 
   Dim codecs As RasterCodecs = New RasterCodecs() 
 
   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp") 
   Dim destFileName1 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_InvertRegion.bmp") 
   Dim destFileName2 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_InvertNoRegion.bmp") 
 
   ' Load the image 
   Dim image As RasterImage = codecs.Load(srcFileName) 
 
   ' The image should have no region 
   Console.WriteLine("After loading, HasRegion = {0}", image.HasRegion) 
   Debug.Assert((Not image.HasRegion)) 
 
   ' Add a region to the image 
   Dim rc As LeadRect = New LeadRect(0, 0, image.Width \ 4, image.Height \ 4) 
   image.AddEllipseToRegion(Nothing, rc, RasterRegionCombineMode.Set) 
 
   ' The image should have a region now 
   Console.WriteLine("After AddEllipseToRegion, HasRegion = {0}", image.HasRegion) 
   Debug.Assert(image.HasRegion) 
 
   ' Invert this image and save it to a file 
   Dim command As InvertCommand = New InvertCommand() 
   command.Run(image) 
   codecs.Save(image, destFileName1, RasterImageFormat.Bmp, 24) 
 
   ' Get rid of the region 
   image.MakeRegionEmpty() 
 
   ' The image should not have a region now 
   Console.WriteLine("After MakeRegionEmpty, HasRegion = {0}", image.HasRegion) 
   Debug.Assert((Not image.HasRegion)) 
 
   ' Invert again and save it 
   command.Run(image) 
   codecs.Save(image, destFileName2, RasterImageFormat.Bmp, 24) 
 
   image.Dispose() 
   codecs.Dispose() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

Reference

RasterImage Class

RasterImage Members

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Help Version 21.0.2021.7.2

Leadtools Assembly

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Getting Started

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Leadtools Namespace

Leadtools.ImageProcessing Namespace

Assemblies