FAQ?
How do I view the parameters to the detectmultiscale function?
To view the parameters to the detectMultiScale function, just fire up a shell, import OpenCV, and use the help function: $ python >>> import cv2 >>> help (cv2.HOGDescriptor ().detectMultiScale) Figure 1: The available parameters to the detectMultiScale function.
Is it possible to implement the detectmultiscale method in Python?
The detectMultiScale function in OpenCV only works with one class. You can implement your own method (as you’ve done), but it will be much slower in Python. Okay thank you, i’m trying that. When i run detectmultiscale or predict, that code uses only 25% of my processor (on rpi 3). Is multiprocessing possible with these methods?
What is the use of rejectlevels in detectmultiscale?
The rejectLevels is a parameter that can be passed as an input parameter looking at the documents. The only output parameter for the detectMultiScale function is objects parameter containing all detections. C++ don't use return variables, filling it up there. However I think the wrapper for python just ignores it for now...
How to use Cascade detectmultiscale to detect faces?
rects = cascade.detectMultiScale (img, scaleFactor=1.3, minNeighbors=4, minSize= (30, 30), flags=cv.CASCADE_SCALE_IMAGE) detectMultiScale function is used to detect the faces. This function will return a rectangle with coordinates (x,y,w,h) around the detected face. It takes 3 common arguments — the input image, scaleFactor, and minNeighbours.