[라즈베리파이 강좌] OpenCV 예제 1.1. 동영상 예제와 얼굴인식 예제 합치기

# import the necessary packages

from picamera.array import PiRGBArray

from picamera import PiCamera

import time

import cv2

def detect(img, cascade):

    rects = cascade.detectMultiScale(img, scaleFactor=1.3, minNeighbors=4, minSize=(30, 30),

                                     flags=cv2.CASCADE_SCALE_IMAGE)

    if len(rects) == 0:

        return []

    rects[:,2:] += rects[:,:2]

    return rects

def draw_rects(img, rects, color):

    for x1, y1, x2, y2 in rects:

        cv2.rectangle(img, (x1, y1), (x2, y2), color, 2)

# initialize the camera and grab a reference to the raw camera capture

camera = PiCamera()

camera.resolution = (640, 480)

camera.framerate = 32

rawCapture = PiRGBArray(camera, size=(640, 480))

cascade = cv2.CascadeClassifier("opencv-3.3.0/data/haarcascades/haarcascade_frontalface_alt.xml")

# allow the camera to warmup

time.sleep(0.1)

# capture frames from the camera

for frame in camera.capture_continuous(rawCapture, format="bgr", use_video_port=True):

    # grab the raw NumPy array representing the image, then initialize the timestamp

    # and occupied/unoccupied text

    img = frame.array

    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

    gray = cv2.equalizeHist(gray)

    rects = detect(gray, cascade)

    vis = img.copy()

    draw_rects(vis, rects, (0, 255, 0))

    # show the frame

    cv2.imshow("Frame", vis)

    key = cv2.waitKey(1) & 0xFF

    # clear the stream in preparation for the next frame

    rawCapture.truncate(0)

    # if the `q` key was pressed, break from the loop

    if key == ord("q"):

        break