python - cv2.error:(-215)s> = 0在函数setSize中

运行代码时出现此错误。我尝试从具有树莓派的网络摄像头中捕获图片，但有时我捕获的第一张图片为空。所以我这样验证

ret, img = cam.read();
        if not ret: continue

我该怎么做才能避免此错误？



我的整个代码是:

def reco(faceDetec):

    recognizer = cv2.face.createLBPHFaceRecognizer()
    recognizer.load("recognizer/trainingData_LBPHF.yml")
    id = 0
    it = 0
    dist = 0
    cam = cv2.VideoCapture(0)
    # prendre les rectangle ayant la plus grde largeur seulement.
    while it < 20:
        ret, img = cam.read();

        if not ret: continue

        cv2.imshow("Face", img);
        cv2.waitKey(1)
        gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
        faces = faceDetec.detectMultiScale(
            img,
            scaleFactor=1.2,
            minNeighbors=7,
            minSize=(50, 50)
            )

        hMax=0
        wHMax=0
        xHMax=0
        yHMax=0
        for (x, y, w, h) in faces:
            if h>hMax:
                hMax=h
                wHMax=w
                xHMax=x
                yHMax=y
        collector = cv2.face.StandardCollector_create()
        recognizer.predict_collect(gray[yHMax:yHMax + hMax, xHMax:xHMax + wHMax], collector)

        if collector.getMinDist()<65:
            it += 1
            dist = dist + collector.getMinDist()
            id = collector.getMinLabel()
            numberOfRec(id)
    cam.release()
    cv2.destroyAllWindows()
    req="SELECT studentId FROM Student WHERE numberOfRec=(SELECT MAX(numberOfRec) FROM Student);"
    cursor.execute(req)
    rows = cursor.fetchall()
    for row in rows:
        id=row[0]
    req="UPDATE Student SET numberOfRec = %(numberOfRec)"
    values = {"numberOfRec": 0}
    cursor.execute(req, values)
    db.commit()
    return id, dist, it

最佳答案

我设法通过添加以下内容来纠正错误:“如果不是img为None:”

def reco(faceDetec):

    recognizer = cv2.face.createLBPHFaceRecognizer()
    recognizer.load("recognizer/trainingData_LBPHF.yml")
    id = 0
    it = 0
    dist = 0
    cam = cv2.VideoCapture(0)
    # prendre les rectangle ayant la plus grde largeur seulement.
    while it < 20:
        ret, img = cam.read();
        if not img is None:
            if not ret: continue

                cv2.imshow("Face", img);
                cv2.waitKey(1)
                gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
                faces = faceDetec.detectMultiScale(
                    img,
                    scaleFactor=1.2,
                    minNeighbors=7,
                    minSize=(50, 50)
                    )

                hMax=0
                wHMax=0
                xHMax=0
                yHMax=0
                for (x, y, w, h) in faces:
                    if h>hMax:
                        hMax=h
                        wHMax=w
                        xHMax=x
                        yHMax=y
                collector = cv2.face.StandardCollector_create()
                recognizer.predict_collect(gray[yHMax:yHMax + hMax,         xHMax:xHMax + wHMax], collector)

                if collector.getMinDist()<65:
                    it += 1
                    dist = dist + collector.getMinDist()
                    id = collector.getMinLabel()
                    numberOfRec(id)
    cam.release()
    cv2.destroyAllWindows()
    req="SELECT studentId FROM Student WHERE numberOfRec=(SELECT MAX(numberOfRec) FROM Student);"
    cursor.execute(req)
    rows = cursor.fetchall()
    for row in rows:
        id=row[0]
    req="UPDATE Student SET numberOfRec = %(numberOfRec)"
    values = {"numberOfRec": 0}
    cursor.execute(req, values)
    db.commit()
    return id, dist, it

关于python - cv2.error:(-215)s> = 0在函数setSize中，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/43557830/