Question

我用OpenCV编写了以下脚本

import cv2
import numpy as np

cap = cv2.VideoCapture(0)
ix, iy = -1, -1

def draw_circle(event, x, y, flags, param):
    global ix
    global iy
    ix,iy = x,y

    if event == cv2.EVENT_LBUTTONDOWN:
        cv2.circle(img, (200, 399), 10, (0, 255, 255), -1)
        print("Text Put")
    elif event == cv2.EVENT_LBUTTONUP:
        print("EVENT_LBUTTONUP")
    elif event == cv2.EVENT_RBUTTONDOWN:
        print("Appuyé Droite")
    elif event == cv2.EVENT_RBUTTONUP:
        print("EVENT_RBUTTONUP")
    elif event == cv2.EVENT_MOUSEMOVE:
        print("Move on", x, y)

while(1):
    ret, img = cap.read()
    cv2.setMouseCallback('image', draw_circle)
    cv2.imshow('image', img)
    if cv2.waitKey(20) & 0xFF == 27:
        break

cv2.destroyAllWindows()

但是当我按下右键时，显示屏上不会出现任何圆圈。我的代码出了什么问题？

Answer 1

此代码段可以帮助您入门：

import cv2
import numpy as np
cap = cv2.VideoCapture(0)
ix, iy = -1,-1

def mouseCallback(event,x,y,flags,param):
    global ix
    global iy

    if event == cv2.EVENT_LBUTTONDOWN:
        ix = x # saves the position of the last click
        iy = y

    elif event == cv2.EVENT_LBUTTONUP:
        print("EVENT_LBUTTONUP")

    elif event == cv2.EVENT_RBUTTONDOWN:
        print("Appuyé Droite")

    elif event == cv2.EVENT_RBUTTONUP:
        print("EVENT_RBUTTONUP")

def draw_circle_onscreen(frame, x,y):
    cv2.circle(frame, (x,y), 10,(0, 0, 255),-1)

cv2.namedWindow('frame')
cv2.setMouseCallback('frame',mouseCallback) # mouse callback has to be set only once

while(1):
    ret, img = cap.read()
    draw_circle_onscreen(img,ix,iy) # draws circle on screen
    cv2.imshow('frame',img)
    if cv2.waitKey(20) & 0xFF == 27:
        break

cv2.destroyAllWindows()

Python Opencv，不要在视频上放置圆圈

1 个答案: