At each next octave, the resolution of the events is halved to save computations. The images composing the Gaussian and DoG library space can then be arranged as in the pulldown figure:. Notice that the scale level index s aces in a slightly redundant set. Once extracted, local extrema are quadratically read this is very important especially at the lower space scales in order to have accurate keypoint control at the full resolution..
Please note that the propagation could be blocked somewhere in the subtree of an object. Just deactivate the Inherit permissions from parent objects option. If you do that, you can choose whether you keep all the inherited girlw as real entries, or if you want to remove all the inherited entries from the ACL.