python鼠标实时点击图片输出像素点的坐标 借助opencv

import cv2

img = cv2.imread("./edge1.png")     #读取图片
a = []
b = []

def on_EVENT_LBUTTONDOWN(event, x, y, flags, param):
    if event == cv2.EVENT_LBUTTONDOWN:
        a.append(x)
        b.append(y)
        cv2.circle(img, (x, y), 3, (255, 0, 0), thickness=-1)
        cv2.imshow("image", img)
        print("[{},{}]".format(a[-1], b[-1]))	#输出最后一次点击的坐标

cv2.namedWindow("image")
cv2.setMouseCallback("image", on_EVENT_LBUTTONDOWN)
cv2.imshow("image", img)
cv2.waitKey(0)
cv2.destroyAllWindows()

效果图1如下：

还有修改的余地，我顺带修改了下
使其在图片中直接标出坐标
代码如下：

import cv2

img = cv2.imread("./edge1.png")     #图片的路径
a = []
b = []

def on_EVENT_LBUTTONDOWN(event, x, y, flags, param):
    if event == cv2.EVENT_LBUTTONDOWN:
        xy = "[%d,%d]" % (x, y)
        a.append(x)
        b.append(y)
        cv2.circle(img, (x, y), 3, (255, 0, 0), thickness=-1)
        cv2.putText(img, xy, (x, y), cv2.FONT_HERSHEY_PLAIN,
                    1.0, (107, 73, 251), thickness=1)	#如果不想在图片上显示坐标可以注释该行
        cv2.imshow("image", img)
        print("[{},{}]".format(a[-1], b[-1]))	#终端中输出坐标

cv2.namedWindow("image")
cv2.setMouseCallback("image", on_EVENT_LBUTTONDOWN)
cv2.imshow("image", img)
cv2.waitKey(0)
cv2.destroyAllWindows()

效果图2如下：

参考here.