TransformJ: Turn

General Description

This plugin enables you to rotate an image multiples of 90 degrees about the z-, y-, and/or x-axis. The reason for using this plugin rather than the more generic Rotate plugin is that it does not involve interpolation of image values but merely a reordering of image elements. Therefore, this plugin generally requires much less computation time.

Description of Dialog Components

z-, y-, x-angle in degrees. The input image can be turned about the z-, y-, and/or x-axis, in that order. The turn operation is repeated for every time frame in every channel of a 5D image.

A right-handed coordinate system is assumed for rotation, where the origin is taken precisely in the center of the image or volume, and where the x-axis is taken horizontally on the screen (with increasing x-coordinate when moving from left to right), the y-axis is taken vertically on the screen (with increasing y-coordinate when moving from top to bottom), and finally the z-axis is taken perpendicular to the screen (with increasing z-coordinate when moving away from the observer, "into the screen").

A rotation of +90 degrees about the z-axis implies that the positive x-axis is mapped onto the positive y-axis. A rotation of +90 degrees about the y-axis maps the positive z-axis onto the positive x-axis. And a rotation of +90 degrees about the x-axis maps the positive y-axis onto the positive z-axis.