Removed assertion that data is z-stack

extensions/chaeo/annotators.py

@@ -33,7 +33,6 @@ def draw_boxes_on_3d_image(yxcz_img, boxes, draw_full_depth=False, **kwargs):
     assert len(yxcz_img.shape) == 4
     nz = yxcz_img.shape[3]
     assert yxcz_img.shape[2] == 1
-    assert nz > 1
 
     annotated = np.zeros(yxcz_img.shape, dtype=yxcz_img.dtype)