如何在 opencv 中更改鼠标 cursor 图像？

Question

I try to develop remote program using c++ and opencv, and I want to change mouse cursor (crosshair).

However, it is difficult to change it in opencv. (In WINAPI, it is possible using Setcursor func)

Is there any method to change cursor image? or hide?

Answer 1

I had the same need, you can do it this way:

import cv2
import win32api
import win32con

def mouse_evt(event, x, y, flags, param):
    # Mouse is Moving
    if event == cv2.EVENT_MOUSEMOVE:
        if some_condition:
            win32api.SetCursor(win32api.LoadCursor(0, win32con.IDC_SIZEALL))

cv2.namedWindow("image")
cv2.setMouseCallback("image", mouse_evt)

while True:
    cv2.imshow("image", image)
    cv2.waitKey(10)

I personally use it to drag cropping point around, the some_condition returns true if the cursor is close to a set point on the image.

Answer 2

I stumbled across this , which doesn't directly apply to us, until you do:

import cv2
import win32api

cv2.namedWindow("my_window")
cv2.setMouseCallback("my_window", mouse_evt)

def mouse_evt(event, x, y, flags, param):
# could also probably do: def mouse_evt(*args):
    win32api.SetCursor(None)

which "hides" the cursor. The problem with this solution is that if the cursor moves, then you may see a flash of one. But if you are willing to get past that, it works like a charm.