gistfile1.py

#!/usr/bin/env python

import numpy as np
import cv2

side_face_fn = "haarcascades/haarcascade_profileface.xml"
cascade_profile = cv2.CascadeClassifier(side_face_fn)

gray = cv2.imread('bug-equed.jpg')

vis = gray.copy()

roi1_coords = (457, 168, 649, 360)

x1, y1, x2, y2 = roi1_coords
cv2.rectangle(vis, (x1, y1), (x2, y2), (255, 255, 255), 1)

roi = gray[y1:y2, x1:x2]
roi_flipped = cv2.flip(roi, 1) 

rects = cascade_profile.detectMultiScale(roi_flipped, scaleFactor=1.3, 
                                         minNeighbors=4, minSize=(30, 30),
                                         flags = cv2.CASCADE_SCALE_IMAGE)
print rects

roi_vis = vis[y1:y2, x1:x2]

# flip the coordinates to draw the rectangle
roi_w = x2 - x1
x, y, w, h = rects[0]
x1 = int(roi_w - x)
y1 = int(y)
x2 = int(roi_w - (x + w))
y2 = int(y + h)

cv2.rectangle(roi_vis, (x1, y1), (x2, y2), (255, 0, 0), 1)



# re-initializing the cascade fixes the bug!
# cascade_profile = cv2.CascadeClassifier(side_face_fn)

roi3_coords = (993, 199, 1173, 379)
x1, y1, x2, y2 = roi3_coords
cv2.rectangle(vis, (x1, y1), (x2, y2), (255, 255, 255), 1)
roi = gray[y1:y2, x1:x2]
rects = cascade_profile.detectMultiScale(roi, scaleFactor=1.3, minNeighbors=4, 
                                         minSize=(30,30), 
                                         flags = cv2.CASCADE_SCALE_IMAGE)
print rects

roi_vis = vis[y1:y2, x1:x2]
x1, y1, w, h = rects[0]
cv2.rectangle(roi_vis, (x1, y1), (x1+w, y1+h), (255, 0, 0), 1)

cv2.imshow('main', vis)

ch = cv2.waitKey()

if ch == 27:
    exit(1)