gtRotateVolume: added possibility to specify the rotation axis position (defaults to center)

Signed-off-by: Nicola Vigano <nicola.vigano@esrf.fr>

zUtil_Imaging/gtRotateVolume.m

-function vol = gtRotateVolume(vol, rot_tensor_angle, rot_axis)
+function vol = gtRotateVolume(vol, rot_tensor_angle, rot_axis, rot_center)
     if (any([size(rot_tensor_angle, 1), size(rot_tensor_angle, 2)] == 1))
         rot_angle = rot_tensor_angle;
         if (~exist('rot_axis', 'var'))
@@ -14,17 +14,19 @@ function vol = gtRotateVolume(vol, rot_tensor_angle, rot_axis)
         rot_tensor = rot_tensor_angle;
     end
     [vol_size(1), vol_size(2), vol_size(3)] = size(vol);
-    vol_center = (vol_size + 1) / 2;
+    if (~exist('rot_center', 'var') || isempty(rot_center))
+        rot_center = (vol_size + 1) / 2;
+    end
 
     T1 = eye(4);
-    T1(4, 1:3) = -vol_center;
+    T1(4, 1:3) = -rot_center;
 
     T2 = eye(4);
     T2(1:3, 1:3) = rot_tensor;
 %     T2(1:3, 1:3) = rot_tensor';
 
     T3 = eye(4);
-    T3(4, 1:3) = +vol_center;
+    T3(4, 1:3) = +rot_center;
 
     T = T1 * T2 * T3;