#!/usr/bin/env python3
# -*- coding: UTF-8 -*-
import cv2
import numpy as np
class HOGBox:
"""
a simple HOG-method-based human tracking box
"""
# mouse click flag
clicked = False
def __init__(self):
print('Initializing HOGBox...')
self.hog = cv2.HOGDescriptor()
self.hog.setSVMDetector(cv2.HOGDescriptor_getDefaultPeopleDetector())
self._box_init_window_name = 'Click mouse to initialize bounding box'
cv2.namedWindow(self._box_init_window_name)
cv2.setMouseCallback(self._box_init_window_name, self.on_mouse)
print('HOGBox initialized.')
def __call__(self, img):
H, W = img.shape[:2]
found, w = self.hog.detectMultiScale(img)
rect = self.cal_rect(found[np.argmax([found[i, 2] * found[i, 3] for i in range(len(found))])], H, W) \
if len(found) else [0, 0, W, H] # biggest area
# rect = self.cal_rect(found[np.argmax(w)], H, W) if len(found) else [0, 0, W, H] # biggest weight
self.draw_rect(img, rect)
scale = 400 / H
img = cv2.resize(img, (0, 0), fx=scale, fy=scale)
cv2.imshow(self._box_init_window_name, img)
if self.clicked:
cv2.destroyWindow(self._box_init_window_name)
return self.clicked, rect
def on_mouse(self, event, x, y, flags, param):
"""
attain mouse clicking message
"""
if event == cv2.EVENT_LBUTTONUP:
self.clicked = True
@staticmethod
def cal_rect(rect, H, W):
"""
calculate the box size and position
"""
x, y, w, h = rect
offset_w = int(0.4 / 2 * W)
offset_h = int(0.2 / 2 * H)
return [np.max([x - offset_w, 0]), # x
np.max([y - offset_h, 0]), # y
np.min([x + w + offset_w, W]) - np.max([x - offset_w, 0]), # w
np.min([y + h + offset_h, H]) - np.max([y - offset_h, 0])] # h
@staticmethod
def draw_rect(img, rect):
"""
draw bounding box in the BB initialization window, and record current rect (x, y, w, h)
"""
x, y, w, h = rect
pt1 = (x, y)
pt2 = (x + w, y + h)
cv2.rectangle(img, pt1, pt2, (60, 66, 207), 4)
