TransformJ: Turn

General Description

This plugin enables one to rotate an image multiples of 90 degrees about the z-, y-, and x-axis. The advantage of using this plugin rather than the more generally applicable Rotate plugin is that it does not involve interpolation of image values but merely a reordering of the image elements. As a result, this plugin generally requires much less computation time, and does not affect image quality.

Dialog Description

z-, y-, x-angle (degrees). The angles (in degrees) of turning about the z-, y-, and x-axis. Turning about the different axes is carried out in that order and the operation is applied to 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, that is "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.