I am trying to make a basic program for a real time face detection. Here's my code (I am a newbie in OpenCV) :
import numpy as np import cv2 cam = cv2.VideoCapture(0) name = 'detect' face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml') cv2.namedWindow(name, cv2.WINDOW_AUTOSIZE) while True: s, img = cam.read() gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) faces = face_cascade.detectMultiScale(gray, 1.3, 5) #print s for (x,y,w,h) in faces: img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) cv2.imshow(name, img) k = cv2.waitKey(0) if k == 27: cv2.destroyWindow("Detect") break
But when I run this code I get this error :
OpenCV Error: Bad flag (parameter or structure field) (Unrecognized or unsupported array type) in cvGetMat, file /build/buildd/opencv-2.4.2+dfsg/modules/core/src/array.cpp, line 2482 Traceback (most recent call last): File "mytry.py", line 27, in <module> cv2.imshow(name, img) cv2.error: /build/buildd/opencv-2.4.2+dfsg/modules/core/src/array.cpp:2482: error: (-206) Unrecognized or unsupported array type in function cvGetMat
I am a newbie in OpenCV ! Please tell me what is wrong with the code, why does this error arises what changes should I make ?
Your line:
img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
will draw a rectangle in the image, but the return value will be None, so img changes to None and cannot be drawn.
Try
cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
Source: Stackoverflow.com