Python中使用cv2库实现绘制动态圆和矩形的方法

import cv2import numpy as npimport copy class Rect(object):     #创建一个类用于接收鼠标点击产生的数据坐标点。     def __init__(self):         self.t1 = (0,0)         self.br = (0,0)         self.r = 0     def regularize(self):         pt1 = (min(self.t1[0],self.br[0]),min(self.t1[1],self.br[1]))         br1 = (max(self.t1[0],self.br[0]),max(self.t1[1],self.br[1]))         self.t1 = pt1         self.br = br1  class DrawRects(object):     def __init__(self,img,color = (0,255,0),thickness = 3):         self.img = img         self.image_for_show = img.copy()         '''        用于覆盖之前的图片，然后在新的空白图片上将以前绘制的图片和目前最新的图片        绘制的到新的图片上。        '''                self.color = color         self.thickness = thickness         self.left_button_down = False #用于判断左键是否按下。         self.current_rect = Rect() #用于接收最新绘制的图形。         self.rects = [] #用于接收绘制的矩形数据。         self.circles = [] #用于接收绘制的圆数据      @staticmethod    def __clip(value,low,high):         output = max(value,low)         output = min(output,high)         return output     def shrink_point(self,x,y):         height,width = self.image_for_show.shape[0:2]         x_shrink = self.__clip(x,0,width)         y_shrink = self.__clip(y,0,height)         return (x_shrink,y_shrink)     '''    上述方法用于限制鼠标点击产生的数据在图片范围内。    '''     def reset_image(self):         self.image_for_show = self.img.copy()     def append(self):         if draw_circle_now:             self.rects.append(['c',copy.deepcopy(self.current_rect)])         else:             self.rects.append(['r',copy.deepcopy(self.current_rect)])       def draw(self):         for rect in self.rects:             if rect[0] == 'r':                 cv2.rectangle(self.image_for_show,rect[1].t1,rect[1].br,color = self.color,thickness=self.thickness)             elif rect[0] == 'c':                 cv2.circle(self.image_for_show,rect[1].t1,rect[1].r,color = self.color,thickness = self.thickness)            def cal_R(self):         self.current_rect.r = int((abs(self.current_rect.br[0] - self.current_rect.t1[0])**2 + abs(self.current_rect.br[1] - self.current_rect.t1[1])**2)**0.5)         #print(self.current_circle.r)         return self.current_rect.r      def draw_current_rect(self):         if draw_circle_now:             self.current_rect.r = self.cal_R()             cv2.circle(self.image_for_show,self.current_rect.t1,self.current_rect.r,color = self.color,thickness=3)         else:             cv2.rectangle(self.image_for_show,self.current_rect.t1,self.current_rect.br,                      color = self.color,thickness = self.thickness)     def pop(self):         rect = Rect()         if self.rects:             rect = self.rects.pop()         return rect  def onmouse_draw_rect(event,x,y,flags,draw_rects):     if event == cv2.EVENT_LBUTTONDOWN:         draw_rects.left_button_down = True         draw_rects.current_rect.t1 = (x,y)     if draw_rects.left_button_down  and event == cv2.EVENT_MOUSEMOVE:         draw_rects.current_rect.br = draw_rects.shrink_point(x,y)         draw_rects.reset_image()         draw_rects.draw()         draw_rects.draw_current_rect()     if event == cv2.EVENT_LBUTTONUP:         draw_rects.left_button_down = False         draw_rects.current_rect.br = draw_rects.shrink_point(x,y)         #draw_rects.current_rect.regularize()         draw_rects.append()     if (not draw_rects.left_button_down) and  event == cv2.EVENT_RBUTTONDOWN:         draw_rects.pop()         draw_rects.reset_image()         draw_rects.draw()    draw_circle_now = False img = np.zeros((516,516,3),np.uint8) draw_rects = DrawRects(img,(0,255,255)) cv2.namedWindow('image') cv2.setMouseCallback('image',onmouse_draw_rect,draw_rects) while True:     cv2.imshow('image',draw_rects.image_for_show)     key = cv2.waitKey(30)     if key == ord('c'):         draw_circle_now = not draw_circle_now     elif key == 27:         break cv2.destroyAllWindows()