Module: Align

Description:

Finds the best translation between two images, using integer translation steps in a window defined by the user. The evaluation function used is the correlation function. Once the best integer translation is found, a natural cubic spline interpolation is used (on a 3x3 window around the integer maximum) to determine an optimal real-valued translation.

Left : reference image, center : model image, right : the two overlapped after the computed translation has been applied to the model.

NOTE:

Image data must be of type float.

Connections:

Model

[required]
The input model images that is to be aligned with the reference image. It is of type HxUniformScalarField3.

Reference

[required]
The input reference image, which is of same type.

Ports:

Window starting point

Coordinates of the translation window's starting point. The module will search for the optimal alignment starting at this translation.

Translation window size

The size of the translation window in which to search for an optimal alignment (positive integer values).

Tiling

When a pixel (x,y,z) of the translated model falls outside the bounds of the reference image, i.e. the pixel in the reference image whose coordinates are (x+Tx,y+Ty,z+Tz), where (Tx,Ty,Tz) is the translation tested, falls outside the reference image, by default that pixel of the model is correlated with a zero value. If tiling is enabled along an axis, say x, the pixel (x,y,z) of the model will be correlated with the pixel (x+Tx mod(W), y+Ty,z+Tz) of the reference, where mod() is the modulo operator and W is the width of the reference image. The same can be applied along the Y and Z axes.

Align

Push this button to start the computation.

Result

Displays the best translation found.

Commands:

Additional options can be accessed when typing in the console Align COMMAND_NAME.

`verbose`

Displays timing information after the computation. Retype to hide info.

`create`

Runs the computation. Returns the name of the output, so it can be used in a script, such as set RESULT [Align create].