These templates are features that are evaluated for your educational image. For example, for function 1a, the learning process finds square areas in all of your training images, where the left half is usually brighter than the right (or vice versa). For function 3a, training finds square areas where the center is darker than the surrounding.
These features that you depicted were chosen for the haar cascade not because they are especially good, but mainly because they are estimated extremely quickly .
, , ( ), . ..
, :
- 1a (x1; y1) - (x2; y2). z1?
(: , ?)
, , , . OpenCV , , .
: - , , . , ( , ).
, ; , ... .
. , ..