Module: LandmarkAlign ()

Description:

This is an experimental module from the Xtra Library: https://xtras.amira-avizo.com.

This module allows computing a linear spatial transformation between a set of landmark pairs, provided as a 'Landmarks (2 sets)' dataset. It allows setting or composing the forward or backward transformation to any spatial data, which can be an image or a surface dataset for instance.

Contrary to the modules 'Landmark Image Warp' or 'Landmark Surface Warp', this module only modifies the spatial transform associated with the data, which is much faster. You may use the modules 'Resample Transformed Image', or 'Apply Transformation' to effectively apply the transformation to the dataset if needed.

Connections:

Data [required]
The pair of landmarks defining the linear transformation.

Landmark pairs are created using Project > Create Object ... > Landmarks (2 sets), and the landmark editor to position alternatively yellow and blue landmarks. The 'Lines' option in the Landmark View module may help visualize the pairs of landmarks, and check that they are effectively in correspondance.

Data To Transform [required]
The Spatial data to be transformed. It can be a grayscale or label image, surface, spatial graph, etc.

Ports:

Direction

Selects whether the transformation should move the yellow landmarks on the blue ones, or vice versa.

Type

Selects the type of linear transformation to be computed.

Actions

• Set: sets the desired transform to the input dataset, regardless of any transform already assigned to the dataset.
• Compose: compose the desired transform with that of the input dataset. Useful if the input dataset already has a spatial transform.
• Reset: reset the transform of the input dataset to identity.
• Print to console: print the desired transformation matrix to the TCL console, using the format of the 'getTransform' command - i.e. you may copy/paste it and use 'setTransform'