Clarification of the detectSURFFeatures 'NumOctaves' parameter

I am looking for clarification on the 'NumOctaves' parameter for detectSURFFeatures, please. The description states that "Each octave spans a number of scales that are analysed using varying size filters".

Therefore, if I specify 3 octaves, does that include octaves 1-2 as well? i.e: filter sizes 9-by-9, 15-by-15, 21-by-21... etc up to and including 99-by-99? Or does it just include the filter sizes from 27-by-27 upwards?

I want to use detectSURFFeatures with the largest possible range of filter sizes. Thanks.

[Chris Williams]

I thought this would be an easy one as it is a standard feature!

Answer 1

[Birju Patel]

Hi Chris,

Yes, it does include octaves 1-2. The 'NumOctaves' parameter controls the total number of octaves.

Hope that helps, Birju