In MeVisLab, the programming of image processing algorithms or interactive image / 3D scene manipulation is basically done by establishing networks that consist of modules and connections between modules. Modules encapsulate certain algorithms written in C++ and provide an interface in MeVisLab in the form of fields. Those fields can represent simple data like numbers or strings, but can also represent more complex data like six dimensional voxel images. Fields of modules of the same type can be connected to form networks that represent algorithms on a higher abstraction layer.

In the following picture, a typical assembly of connected modules in a network, their panels, and viewers can be seen.

Figure 3.1. Example Network for SynchroView2D with Viewer (Panel), Automatic Panel, and Settings

The following information can be found in this chapter:

For module and network shortcuts, see Section 4.3.10, “Preferences — Shortcuts”.

3.1. Types of Modules

There are three types of modules:

Table 3.1. Module Types

Type	Look	Characteristics
ML Module (blue)		page-based, demand-driven processing of voxels
Open Inventor (So) Modules (green)		visual scene graphs (3D)
Macro Module (brown)		combination of other module types, allowing implementing hierarchies and scripted interaction

If a module is invalid, it is displayed in bright red.

The number of warning and error messages that are being printed to the debug console are listed at the upper right corner of the module. Once the debug console is cleared, the warning and error indicators at the module are also cleared. If the module produces information messages, their number is printed in gray at this position. This enables a network or module developer to find the modules in a network that produce messages quickly.

Table 3.2. Invalid Modules

Module Appearance	Explanation
	Invalid module
	Macro containing an invalid module

For information and examples on how to construct networks from modules, please refer to the Getting Started in which image processing pipelines, scene graphs and macro module creation are discussed in detail.