Tutorial Introduction

Welcome to MeVisLab!

More than 20 years of experience and the continuous implementation of adaptations made MeVisLab one of the most powerful development platforms for medical image processing. Several applications and their prototypes are based on and could be realized because of MeVisLab, including software assistants for neuro-imaging, dynamic image analysis, surgery planning, and cardiovascular analysis.

MeVisLab is a development environment for rapid prototyping and product development of medical and industrial imaging applications. It includes a Software Development Kit (SDK) and an ApplicationBuilder for deploying your applications to end-customers.

In turn, the MeVisLab SDK consists of an Integrated Development Environment (IDE) for visual programming and the advanced text editor MATE for Python scripting, providing code completion, debugging, profiling and automated test development as well as execution.

You can re-use thousands of pre-defined Modules for image processing (2D up to 6D images) and visualization, combine them or even build your own.

A quick introduction on available modules and example networks will be given in the following tutorials.

Structure and usage of provided tutorials

This tutorial is a hands-on training. You will learn about basic mechanics and features of MeVisLab.

Starting with this introduction, we will be leading you through all relevant aspects of the user interface, commonly used functionalities and provide you with all the basic knowledge you need to build your own web applications.

Additional information is accessible through embedded links, forwarding you to a related glossary entry or tutorial and shortcuts, advice and hints will be highlighted as shown here.

The tutorials are divided into chapters by their topic and each chapter contains at least one example for you to try. You find them at the end of the tutorial or, also sorted by chapters, under the menu entry Examples. The examples under the designated menu entry are more suitable if you already have a little experience and rather search for inspiration than for explanations.

Starting MeVisLab for the first time

Right after installation of MeVisLab, you will find some new icons on your Desktop (if selected during setup).

Use the top middle icon to start the MeVisLab IDE. You can also start the integrated text editor MATE or the ToolRunner. For this tutorial, you will generally require the IDE.

MeVisLab IDE User Interface

First, start the MeVisLab IDE. After the Welcome Screen, the standard user interface opens.

Workspace

By default, MeVisLab starts with an empty workspace.

This is where you will be developing and editing networks. Networks essentially form the base of all processing and visualization pipelines, so the workspace is, where the visual programming is done.

Views Area

The standard Views Area contains the Output Inspector and Module Inspector. With the help of the Output Inspector, you can visualize the modules output.

Debug Output

Debugging information can be found using the Debug Output.

The MeVisLab IDE and its layout are completely configurable. You can rearrange the items and add new views via [ Main Menu → View → Views ].

Filetypes used in, for and with MeVisLab

Module types

The three existing module types (ML, Open Inventor and macro module) can be distinguished by their colors:

Invalid modules

If a module is invalid, it is displayed in bright red. This might happen if the module itself is not available for your system.

As you can see, the number of warning and error messages that are being printed to the debug console are listed in the upper right corner of the module. This is intentional, as it enables the developer to quickly find the module causing the errors.

Informational messages are indicated in a similar matter on the same spot, but in a subtle grey color.

Module interactions through the Context Menu

Each module has a context menu, providing the following options:

• Show Internal Network: Macro modules provide an entry to open the internal network. You can see what happens inside a macro module. The internal network may also contain other macro modules.
• Show Window: If a module does not provide an User Interface, you will see the automatic panel, showing the module’s name. Modules may additionally have one or more windows which can be opened. You can also open the Scripting Console of a module to integrate Python.
• Instance Name: You can edit or copy the instance name. Renaming can be useful if the same module appears more than once in one network and/or if you want to access and distinguish the modules in your Python script.
• Help: The menu entry Help provides access to the Module Help pages and to an example network where the module is used. This example network often helps to understand which additional modules can be added to create your desired effect.
• Extras: Automated tests written for the specific module can be executed here. You can also run this module in a separate process.
• Reload Definition: In case you are currently working on a module, you may need to reload the definition so that your changes are applied on the module (for example attached Python scripts).
• Related Files: Related files allows a quick access to the modules *.script or *.py files. The files are automatically opened in MATE for editing.
• Show Enclosing Folder: This entry opens the directory where your module is stored.
• Grouping: Multiple modules can be clustered and the groups can be named. This adds clarity to the structure of your network. In addition to that, grouped modules can be converted to local- or global macro modules easily.

Input and Output Connectors

As the creation of a network requires connected modules, each module has input and output connectors, located on their top and bottom side. Data is transmitted from the output connector on the top side of one module to the input connector on another module’s bottom side.

Once again, three types can be distinguished:

Some modules even contain hidden connectors in addition to the ones displayed on the module’s surface. Click on the workspace and press SPACE to see the hidden connectors as well as the internal networks of each module. You can now also use the hidden connectors for building connections.

For more information about connectors and different types of connections click here .
If you want to know more about establishing, interrupting, moving and replacing connections, have a look at this.

Parameter Connections

Besides through a module’s input and output connectors, connections can also be established between parameters in the module’s panel.

Macro modules

Adding modules to your workspace

There are several ways to add a module to your current network:

• via the menu bar entry [ Modules ].
• via [ Quick Search ].
• via the View Module Search.
• via the View Module Browser.
• via copy and paste from another network.
• by scripting, see the Scripting Reference

Both the menu entry[ Modules ] and the Module Browser display all available modules. The modules are sorted hierarchically by topic and name, as defined in the file Genre.def.

Therefore, both places are a good starting point when in need of a specific function, like an ImageLoad module.

The advantage of the Module Browser is that you can right-click the entries, open the context menu and, for example, open the help (in your default Internet browser) or the module files (in MATE, the in-built text editor).

Usually the quickest way to add modules to a network is the quick search in the menu bar. It offers you the possibility to search for modules by module name. By default, the search will also be extended to keywords and substrings and is case-insensitive. To change these settings, click the magnifier button for the search options.

Use the ↑ ArrowUp and ↓ ArrowDown keys on your keyboard to move to one of the listed modules. The module’s decription will appear next to it, allowing you to decide if this is the right module for your use-case.