使用 python 和 opencv 计算人脸
count faces with python and opencv
我在 python 中有使用 opencv2 检测人脸的脚本。我在网络摄像头中拍摄视频并使用 Haar Cascade 检测人脸。我想摆脱一帧中检测到的人脸数量。我知道这可以通过在找到一张脸时计算矩形来完成。怎么做?如何计算一帧中的矩形?
import cv2
import sys
faceCascade = cv2.CascadeClassifier("haarcascade_frontalface_default.xml")
video_capture = cv2.VideoCapture(0)
while True:
# Capture frame-by-frame
ret, frame = video_capture.read()
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
faces = faceCascade.detectMultiScale(
gray,
scaleFactor=1.1,
minNeighbors=5,
minSize=(30, 30),
flags=cv2.CASCADE_SCALE_IMAGE
)
# Draw a rectangle around the faces
for (x, y, w, h) in faces:
cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)
# Display the resulting frame
cv2.imshow('Video', frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
# When everything is done, release the capture
video_capture.release()
cv2.destroyAllWindows()
简单使用len(faces)
应该return面数
我在 python 中有使用 opencv2 检测人脸的脚本。我在网络摄像头中拍摄视频并使用 Haar Cascade 检测人脸。我想摆脱一帧中检测到的人脸数量。我知道这可以通过在找到一张脸时计算矩形来完成。怎么做?如何计算一帧中的矩形?
import cv2
import sys
faceCascade = cv2.CascadeClassifier("haarcascade_frontalface_default.xml")
video_capture = cv2.VideoCapture(0)
while True:
# Capture frame-by-frame
ret, frame = video_capture.read()
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
faces = faceCascade.detectMultiScale(
gray,
scaleFactor=1.1,
minNeighbors=5,
minSize=(30, 30),
flags=cv2.CASCADE_SCALE_IMAGE
)
# Draw a rectangle around the faces
for (x, y, w, h) in faces:
cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)
# Display the resulting frame
cv2.imshow('Video', frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
# When everything is done, release the capture
video_capture.release()
cv2.destroyAllWindows()
简单使用len(faces)
应该return面数