Python的Opencv初学部分知识点（一）

cv.bitwise_not（） 像素取反

如：

def inverse(image):
    dst = cv.bitwise_not(image)
    cv.imshow("image demo",dst)

cv.inRange（） 过滤视频中需求颜色像素

def extrace_object():
    capture = cv.VideoCapture("D:/hecheng.mp4")
    while True:
        ret,frame = capture.read()
        if ret == False:
            break;
        hsv = cv.cvtColor(frame,cv.COLOR_BGR2HSV)
        lower_hsv = np.array([37,43,46])
        upper_hsv = np.array([77,255,255])
        mask = cv.inRange(hsv,lowerb=lower_hsv,upperb=upper_hsv)
        cv.imshow("mask",mask)
        cv.imshow("Video",frame)
        c = cv.waitKey(40)
        if  c == 27:
            break;

b,g,r = cv.split(src) 图像通道分离

b,g,r = cv.split(src)
cv.imshow("blue",b)
cv.imshow("green",g)
cv.imshow("red",r)

src = cv.imread("timg.jpg")

//修改某一个通道的值

src[:,:,2] = 0 

cv.imshow("timg",src)

cv.merge() 将几个通道的图片拼合起来

src = cv.merge([b,g,r])
cv.imshow("Demo",src)