Python利用cv2动态绘制圆和矩形的示例详解

新手,参考了以下链接:

本文可以实现在指定图片上动态绘制圆和矩形。

import cv2
import numpy as np
import 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()
作者:weixin_66412464原文地址:https://blog.csdn.net/weixin_66412464/article/details/125356885

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