用python中opencv检测人脸和眼睛
时间: 2023-09-28 09:05:22 浏览: 47
要使用Python中的OpenCV检测人脸和眼睛,可以按照以下步骤操作:
1. 安装OpenCV库:
```
pip install opencv-python
```
2. 下载并导入人脸和眼睛检测器:
```python
import cv2
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')
```
3. 读取图像并将其转换为灰度:
```python
img = cv2.imread('image.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
```
4. 使用人脸检测器检测人脸:
```python
faces = face_cascade.detectMultiScale(gray, 1.3, 5)
```
5. 对于每个检测到的人脸,使用眼睛检测器检测眼睛:
```python
for (x,y,w,h) in faces:
cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) # 在图像上绘制矩形框
roi_gray = gray[y:y+h, x:x+w] # 灰度图像中的人脸区域
roi_color = img[y:y+h, x:x+w] # 原始图像中的人脸区域
eyes = eye_cascade.detectMultiScale(roi_gray)
for (ex,ey,ew,eh) in eyes:
cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2) # 在人脸区域中绘制眼睛矩形框
```
6. 显示结果:
```python
cv2.imshow('img',img)
cv2.waitKey(0)
cv2.destroyAllWindows()
```
完整代码如下:
```python
import cv2
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')
img = cv2.imread('image.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)
for (x,y,w,h) in faces:
cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
roi_gray = gray[y:y+h, x:x+w]
roi_color = img[y:y+h, x:x+w]
eyes = eye_cascade.detectMultiScale(roi_gray)
for (ex,ey,ew,eh) in eyes:
cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)
cv2.imshow('img',img)
cv2.waitKey(0)
cv2.destroyAllWindows()
```