Draw and Edit Annotations on Images - WinForms C#

This tutorial shows how to use the automated annotation features of the LEADTOOLS SDK in a WinForms C# application.

Overview  
Summary This tutorial covers automated annotation features in a C# WinForms Application.
Completion Time 30 minutes
Visual Studio Project Download tutorial project (211 KB)
Platform WinForms C# Application
IDE Visual Studio 2017, 2019
Development License Download LEADTOOLS

Required Knowledge

Before working on the Draw and Edit Annotations on Images - WinForms C# tutorial, get familiar with the basic steps of creating a project by reviewing the Add References and Set a License tutorial.

Create the Project and Add LEADTOOLS References

Create a new C# Windows Winforms project, and add the below necessary LEADTOOLS references.

The references needed depend upon the purpose of the project. References can be added by one or the other of the following two methods (but not both). For this project, the following references are needed:

If NuGet references are used, this tutorial requires the following NuGet package:

If local DLL references are used, the following DLLs are needed. The DLLs are located at <INSTALL_DIR>\LEADTOOLS21\Bin\Dotnet4\x64:

For a complete list of which Codec DLLs are required for specific formats, refer to File Format Support.

Set the License File

The License unlocks the features needed for the project. It must be set before any toolkit function is called. For details, including tutorials for different platforms, refer to the Setting a Runtime License tutorial.

There are two types of runtime licenses:

Note

Adding LEADTOOLS NuGet and local references and setting a license are covered in more detail in the Add References and Set a License tutorial.

Add the Automation Annotation Code

With the project created, the references added, and the license set, coding can begin.

Go to Form1.cs in the Solution Explorer. Click the Events icon in the Properties Windows. Then, double-click the Load event to create an event handler.

Creating a Load event

Add the following code to the using block and the global variables.

C#
// Using block at the top 
using System; 
using System.Windows.Forms; 
using Leadtools; 
using Leadtools.Controls; 
using Leadtools.Codecs; 
using Leadtools.Annotations.Automation; 
using Leadtools.Annotations.WinForms; 
C#
// Add global variables 
private ImageViewer viewer; 
private ImageViewerAutomationControl automationControl; 
private AnnAutomationManager annAutomationManager; 
private AnnAutomation automation; 

Add the following code inside the Form1_Load event handler.

C#
private void Form1_Load(object sender, EventArgs e) 
{ 
   // Initialize Image Viewer object 
   viewer = new ImageViewer(); 
   viewer.Dock = DockStyle.Fill; 
 
   // Initialize Automation Control for Image Viewer 
   automationControl = new ImageViewerAutomationControl(); 
   automationControl.ImageViewer = viewer; 
 
   // Initialize a new RasterCodecs object  
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Load the main image into the viewer  
   viewer.Image = codecs.Load(@"C:\LEADTOOLS21\Resources\Images\ocr1.tif"); 
 
   // Initialize the Interactive Mode for the Image Viewer  
   AutomationInteractiveMode automationInteractiveMode = new AutomationInteractiveMode(); 
   automationInteractiveMode.AutomationControl = automationControl; 
 
   // Add the Interactive Mode to the Image Viewer  
   viewer.InteractiveModes.BeginUpdate(); 
   viewer.InteractiveModes.Add(automationInteractiveMode); 
   viewer.InteractiveModes.EndUpdate(); 
 
   if (viewer.Image != null) 
   { 
      // Create and set up the Automation Manager  
      annAutomationManager = new AnnAutomationManager(); 
      annAutomationManager.RestrictDesigners = true; 
 
      // Instruct the Manager to create all the default Automation objects.  
      annAutomationManager.CreateDefaultObjects(); 
 
      // Initialize the Manager Helper and create the Toolbar 
      // Add the Toolbar and the Image Viewer to the Controls  
      AutomationManagerHelper managerHelper = new AutomationManagerHelper(annAutomationManager); 
      managerHelper.CreateToolBar(); 
      Controls.Add(managerHelper.ToolBar); 
      Controls.Add(viewer); 
 
      // Set up the Automation (it will create the Container as well)  
      automation = new AnnAutomation(annAutomationManager, automationControl); 
      // Set this Automation as the active one  
      automation.Active = true; 
 
      // Set the size of the Container to the size of the Image Viewer  
      automation.Container.Size = automation.Container.Mapper.SizeToContainerCoordinates(LeadSizeD.Create(viewer.Image.ImageWidth, viewer.Image.ImageHeight)); 
   } 
} 

This tutorial uses this sample image from the LEADTOOLS Images folder here: <INSTALL_DIR>\LEADTOOLS21\Resources\Images.

Run the Project

Run the project by pressing F5, or by selecting Debug -> Start Debugging.

If the steps were followed correctly, the application runs and the sample image is loaded into the viewer. Any of the annotations on the toolbar can be selected and used to draw on the image. The following image shows an example of a portion of the image in the viewer, with the annotation toolbar at the top of the viewer.

Viewer showing some annotations drawn on an image

Wrap-up

This tutorial showed how to use the ImageViewerAutomationControl, AnnAutomationManager, AnnAutomation, and AutomationInteractiveMode classes.

See Also

Help Version 21.0.2020.9.16
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2020 LEAD Technologies, Inc. All Rights Reserved.