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python 涉及opencv mediapipe知识，眨眼计数供初学者参考

news 2025/8/3 17:59:09

基本思路我们知道正面侦测到人脸时，任意一只眼睛水平方向上的两个特征点构成水平距离，上下两个特征点构成垂直距离当头像靠近或者远离摄像头时，垂直距离与水平距离的比值基本恒定

根据这一思路当闭眼时垂直距离变小比值固定小于某一个值当睁眼时比值大于某个比率，比如35%，我们将比值扩大一百倍（35% X 100）这样我们认为大于35时是睁眼小于为闭眼，根据程序侦测画面帧数我们认为某一段连续的帧画面就是同一个事件所以我们只处理其中一帧画面。基本背景知识需要用到mediapipe中人脸模型下面给出右眼特征点编号

完整代码：

import cv2
import cvzone
from cvzone.FaceMeshModule import FaceMeshDetector
from cvzone.PlotModule import  LivePlot
from PIL import Image, ImageDraw, ImageFont
import numpy as npdef putText2(img,text,pos,size=36,color=(255,0,0)):img_pil = Image.fromarray(cv2.cvtColor(img, cv2.COLOR_BGR2RGB))font = ImageFont.truetype(font=r'simsun.ttc', size=size)draw = ImageDraw.Draw(img_pil)draw.text(pos, text, font=font, fill=color)  # PIL中RGB=(255,0,0)表示红色img_cv = np.array(img_pil)                         # PIL图片转换为numpyimg = cv2.cvtColor(img_cv, cv2.COLOR_RGB2BGR)      # PIL格式转换为OpenCV的BGR格式return imgcap=cv2.VideoCapture("out.mp4")
detector=FaceMeshDetector(maxFaces=1)
#绘制Y坐标为20到50之间的实时波形图,宽度 高度 范围
plotY=LivePlot(480,640,[20,50],invert=True)
idEyeList=[22,23,24,26,110,157,158,159,160,161,162,130]ratioList=[]
blinkCouter=0
counter=0
color=(255,0,255)
while True:if cap.get(cv2.CAP_PROP_POS_FRAMES)==cap.get(cv2.CAP_PROP_FRAME_COUNT):cap.set(cv2.CAP_PROP_POS_FRAMES,0)success,img=cap.read()# print(img.shape)img, faces = detector.findFaceMesh(img,draw=False)if faces:face=faces[0]for id in idEyeList:cv2.circle(img,face[id],5,(255,0,255),cv2.FILLED)cv2.line(img,face[159],face[23],(0,255,0),1)cv2.line(img, face[130], face[243], (0, 255, 0), 1)leftUp=face[159]leftDown=face[23]leftLeft=face[130]leftRight=face[243]#垂直距离与水平距离lengthVer,_=detector.findDistance(leftUp,leftDown)lengthHor, _ = detector.findDistance(leftLeft,leftRight)# print("比率",lengthVer/lengthHor)#获取随时变化的值ratio=int((lengthVer/lengthHor)*100)#让波形看起来平滑ratioList.append(ratio)if len(ratioList)>10:ratioList.pop(0)ratioAvg=sum(ratioList)/len(ratioList)# imgPlot=plotY.update(ratio)if ratioAvg<40 and counter==0:blinkCouter += 1color=(0,255,0)counter=1if counter !=0:counter +=1#保持20毫秒内不重复计数if counter>20:color=(255,0,255)counter=0# cvzone.putTextRect(img,f'blink count:{blinkCouter}',(50,50),colorR=(0,255,0))cv2.rectangle(img,(50,50),(260,85),color,cv2.FILLED)img=putText2(img,f'眨眼计数:{blinkCouter}',(50,50),color=(0,0,255))imgPlot = plotY.update(int(ratioAvg),color)# cv2.imshow("Imgplot",imgPlot)cv2.resize(img, (640, 480))imgStack=cvzone.stackImages([img,imgPlot],2,1)cv2.imshow("img",imgStack)cv2.waitKey(1)

截取任意一帧画面演示效果：