text: #!/usr/bin/env python
  
  '''
  example to detect upright people in images using HOG features
  
  Usage:
      peopledetect.py <image_names>
  
  Press any key to continue, ESC to stop.
  '''
  
  # Python 2/3 compatibility
  from __future__ import print_function
  
  import numpy as np
  import cv2 as cv
  
  
  def inside(r, q):
      rx, ry, rw, rh = r
      qx, qy, qw, qh = q
      return rx > qx and ry > qy and rx + rw < qx + qw and ry + rh < qy + qh
  
  
  def draw_detections(img, rects, thickness = 1):
      for x, y, w, h in rects:
          # the HOG detector returns slightly larger rectangles than the real objects.
          # so we slightly shrink the rectangles to get a nicer output.
          pad_w, pad_h = int(0.15*w), int(0.05*h)
          cv.rectangle(img, (x+pad_w, y+pad_h), (x+w-pad_w, y+h-pad_h), (0, 255, 0), thickness)
  
  
  def main():
      import sys
      from glob import glob
      import itertools as it
  
      hog = cv.HOGDescriptor()
      hog.setSVMDetector( cv.HOGDescriptor_getDefaultPeopleDetector() )
  
      default = [cv.samples.findFile('basketball2.png')] if len(sys.argv[1:]) == 0 else []
  
      for fn in it.chain(*map(glob, default + sys.argv[1:])):
          print(fn, ' - ',)
          try:
              img = cv.imread(fn)
              if img is None:
                  print('Failed to load image file:', fn)
                  continue
          except:
              print('loading error')
              continue
  
          found, w = hog.detectMultiScale(img, winStride=(8,8), padding=(32,32), scale=1.05)
          found_filtered = []
          for ri, r in enumerate(found):
              for qi, q in enumerate(found):
                  if ri != qi and inside(r, q):
                      break
              else:
                  found_filtered.append(r)
          draw_detections(img, found)
          draw_detections(img, found_filtered, 3)
          print('%d (%d) found' % (len(found_filtered), len(found)))
          cv.imshow('img', img)
          ch = cv.waitKey()
          if ch == 27:
              break
  
      print('Done')
  
  
  if __name__ == '__main__':
      print(__doc__)
      main()
      cv.destroyAllWindows()
  