Opencv_traincascades and Rotations


How much rotations does the opencv_traincascades support? I believe Haar suppose 45 degree, but does it also suppose negative 45 degree rotation ?

Does it suppose all other angular rotations ?

“suppose” ==> “support”, i guess…

where do you get that from ?

are you confusing it with tilted haar features ?

no, not at all. it is just slightly “robust” against minimal rotation, like +=10°

I meant support.

Nice diagram, I thought the original specs of 45 degree support is in OpenCV, but I’m not sure of the tilted features. Are they also there?

You are inferring that only slight -/+10 degrees rotation is supported in OpenCV???

just look at the haar features:

detecting those will clearly degrade with rotation

also, training with a large variety of angles will “smear” the detection later

they were added to the opencv library very early

may i ask you, what you want to detect later, and under which conditions ?

Simply trying to see if it supports various angular rotations because using opencv_traincascade featureType ALL is meant to support different orientations although I think I read that it supports only 45 degrees, and I’m not sure if it is positive or negative 45 degrees, but from my observation, is quite vague on the slightness of angle it supports, meaning it is not clear. That feature (ALL instead of CORE) increases training time significantly.

If the support is there built-in, no need for me to improvise if I use it to detect objects (it saves me time)