python打开相机，用鼠标左键框选矩形区域，支持一次框选多个矩形区域，通过鼠标右标清除上一次画的矩形。

方案一

import cv2# Global variables
rectangles = []
current_rectangle = []
drawing = False# Mouse callback function
def mouse_callback(event, x, y, flags, param):global rectangles, current_rectangle, drawingif event == cv2.EVENT_LBUTTONDOWN:drawing = Truecurrent_rectangle = [(x, y)]elif event == cv2.EVENT_LBUTTONUP:drawing = Falsecurrent_rectangle.append((x, y))rectangles.append(tuple(current_rectangle))current_rectangle = []elif event == cv2.EVENT_RBUTTONDOWN:rectangles.pop()# Open camera
cap = cv2.VideoCapture(0)# Create a window and set mouse callback
cv2.namedWindow('Camera')
cv2.setMouseCallback('Camera', mouse_callback)while True:# Read frame from cameraret, frame = cap.read()# Draw rectangles on the framefor rect in rectangles:cv2.rectangle(frame, rect[0], rect[1], (0, 255, 0), 2)# Display the framecv2.imshow('Camera', frame)# Check for key presskey = cv2.waitKey(1)if key == 27:  # Press 'Esc' to exitbreak# Release the camera and destroy all windows
cap.release()
cv2.destroyAllWindows()

方案二

import cv2# Global variables
rectangles = []
current_rectangle = []
drawing = False
rect_x = 0
rect_y = 0# Mouse callback function
def mouse_callback(event, x, y, flags, param):global rectangles, current_rectangle, drawingif event == cv2.EVENT_LBUTTONDOWN:drawing = Truecurrent_rectangle = [(x, y)]global rect_x, rect_yrect_x = xrect_y = yelif event == cv2.EVENT_LBUTTONUP:drawing = Falsecurrent_rectangle.append((x, y))rectangles.append(tuple(current_rectangle))current_rectangle = []elif event == cv2.EVENT_RBUTTONDOWN:rectangles.pop()# Open camera
cap = cv2.VideoCapture(0)# Create a window and set mouse callback
cv2.namedWindow('Camera')
cv2.setMouseCallback('Camera', mouse_callback)while True:# Read frame from cameraret, frame = cap.read()# Draw rectangles on the framefor rect in rectangles:cv2.rectangle(frame, rect[0], rect[1], (0, 255, 0), 2)# Draw current rectangle in real-timeif drawing:cv2.rectangle(frame, current_rectangle[0], (rect_x, rect_y), (0, 255, 0), 2)# Display the framecv2.imshow('Camera', frame)# Check for key presskey = cv2.waitKey(1)if key == 27:  # Press 'Esc' to exitbreak# Release the camera and destroy all windows
cap.release()
cv2.destroyAllWindows()

下一步修改优化

a 在图像区域内实时显示鼠标所在位置的十字线

b 实时显示绘制框的过程