Image Annotation & Markup Customizable Features

LEADTOOLS SDKs include flexible and time-tested document and image annotation libraries for .NET (C#, VB, Core, Xamarin, UWP), C, C++, iOS, macOS, Linux, Java, and web developers. LEADTOOLS Annotation technology offers many customizable features, flexible development options, and a robust user experience.

Customizable Annotation Features Include:

 Custom Annotations

LEADTOOLS includes more than 30 built-in annotation objects that can be extended to create custom annotation objects. Developers can change the way the user interacts with existing annotations as well as create completely new annotation objects such as Triangle, Shutter, Text Bubble, Bull's-eye, and Permanent Magnifying Glass—the possibilities are endless with LEADTOOLS Annotations!

 User Interface (Toolbars, Context Menus, and Dialogs)

LEADTOOLS provides an extensive collection of objects, toolbars, menus, and dialogs within its .NET (C#, VB, Core, Xamarin, UWP), C, C++, iOS, macOS, Linux, Java, and web annotations, which can be customized to best suit your application and targeted end-users. All user interface elements can be directly accessed to change strings, images, and event handlers. Additionally, dialog and menu strings can be localized using standard .NET Globalization and Localization to provide country/region specific versions of your application with minimal code.

 XML Annotation Save Format

LEADTOOLS annotations can be stored in multiple formats, but the XML (Extensible Markup Language) format is the most popular. There are many advantages of using the XML format, including:

  • XML is forward and backward compatible
  • XML is human readable
  • XML is easily modified using a standard text editor
  • XML is easily parsed using any standard XML parser
  • XML is used with any of the growing number of applications and utilities that work with XML

 Annotation Rotate Option

With the rotate options interface, two rotate handles are displayed on a selected object. One of the handles is the "gripper" handle, which rotates the object when dragged. The other handle is the "center" handle, which determines the axis of rotation. The center and gripper handles can be moved by clicking and dragging.

The following figure illustrates a rotate by dragging the gripper handle:

annotation gripper handle

The following figure illustrates moving the center handle:

annotation center handle

 Calibrate Ruler Feature

With this feature, a user can automatically calibrate a ruler to the desired size. This is useful to allow a user to interactively measure something in an image. Any of the measurement type annotation objects can be calibrated using the Ruler Calibrate Automation Dialog.

Calibration for Ruler Annotation Object Types

 Annotation Cursors

This feature displays different cursors for many tasks in automated annotation mode. This feature displays unique annotation cursors in the following situations:

  • When hovering over a rotation gripper handle
  • When hovering over a rotation center handle
  • When hovering over any of the eight size handles and an appropriate arrow cursor is displayed depending on the handle and the rotation of the annotation object
  • When dragging a selection
  • When using any of the 30 annotation tools

All annotation cursors may be changed to your own custom cursor.

The following figure displays some of the default cursors:

Default Annotation Cursors

 Alpha Background Fill Option

LEADTOOLS annotation objects support an alpha option to specify an alpha value from 0 (completely transparent background) to 255 (completely opaque background).

The following figure displays rectangle annotation objects with different alpha values:

Annotation Object Alpha

 Dot Dash Lines

Most of the LEAD annotation objects have Line Width and Line Style options. These options can be used to draw the annotations with varying line thicknesses and change the line style to solid, dashed, or dotted.

The following example illustrates this:

Annotation Line Styles

 Text Annotation Options

Text annotation object options include:

  • Text visibility
  • Text color
  • Text Alignment
  • Font style and size
  • Border visibility
  • Border color

Annotation Text Object Styles

Start Coding With LEADTOOLS Image Annotation & Markup Customizable Features


Image Annotation & Markup Customizable Features libraries for Windows, Linux, and macOS as well as all LEADTOOLS Recognition, Document, Medical, Vector, and Imaging technologies for all development and target platforms.

Download LEADTOOLS Libraries

Online Demo Applications that include Image Annotation & Markup Customizable Features

HTML5/JavaScript Annotations

Uses LEADTOOLS annotations and image-markup libraries to add stamps, sticky notes, rulers, and various other image markup devices to an annotation layer of the image without changing the original image data.

  • Draw annotations
  • Export image

HTML5/JavaScript Medical Web Viewer Framework

A zero-footprint Medical viewer with light and dark themes to display DICOM images (pixel data) with window level, density removal, offset, scale, zoom, stack, annotation/markup, and multi-touch support for phone, tablet, and desktop.

It demonstrates zero-footprint 3D volume rendering of multiple volume types including VRT, MIP, MPR, and SSD in the Medical Web Viewer. The viewer does not require browser plugins, desktop utilities, or remote desktop clients and options for low-resolution and caching to speed up rendering and loading.

Note: If you have your own test images that you would like to upload into the application, contact support@leadtools.com to have a private user profile created.

HTML5/JavaScript Dental Web Viewer Framework

The zero-footprint Medical Web Viewer with specialized dental features enabled, including Endo, Perio, Dentin, and FMX layouts. Additionally shows multi-touch support for phone, tablet, and desktop.

  • Interactive brightness and contrast display
  • Display DICOM information

Mobile Demo App

Use the LEADTOOLS Annotations App to annotate (mark-up) images without changing the image data. Add many annotation object types.