gtRotateVolume: performance optimization thanks to affine3d

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

zUtil_Imaging/gtRotateVolume.m

@@ -13,25 +13,19 @@ function vol = gtRotateVolume(vol, rot_tensor, rot_axis)
     T1(4, 1:3) = -vol_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;
 
     T = T1 * T2 * T3;
 
-    tform = maketform('affine', T);
-%     new_center = tformfwd(vol_center, tform)
+    tform = affine3d(T);
+    vol = imwarp(vol, tform, 'OutputView', imref3d(size(vol)));
 
-    R = makeresampler('linear', 'fill');
-    vol = tformarray(vol, tform, R, [1 2 3], [1 2 3], vol_size, [], 0);
+    % Old version. NOTE that rot_tensor should be un-transposed if this
+    % version was to be used.
+%     tform = maketform('affine', T);
+%     R = makeresampler('linear', 'fill');
+%     vol = tformarray(vol, tform, R, [1 2 3], [1 2 3], vol_size, [], 0);
 end
-
-% function vol = gtRotateVolume(vol, angle, method)
-%     if (~exist('method', 'var'))
-%         method = 'nearest';
-%     end
-%     for ii_s = 1:size(vol, 3)
-%         vol(:, :, ii_s) = imrotate(vol(:, :, ii_s), angle, method, 'crop');
-%     end
-% end
\ No newline at end of file