Python OpenCV实现鼠标绘制矩形框和多边形

目录

Python OpenCV实现鼠标绘制矩形框和多边形

1. OpenCV鼠标事件操作说明

（1）setMouseCallback函数说明

（2）回调函数onMouse说明

（3）event 具体说明：

（4）flags 具体说明

2. OpenCV实现鼠标绘制矩形框和多边形框

（1）绘制矩形框

（2）绘制多边形

（3）键盘控制

3. 完整的代码

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本篇将使用OpenCV开发一个简易的绘图工具，可以实现鼠标绘制矩形框和多边形，先看一下Demo效果

 源码已经开源在GitHub， 开源不易,麻烦给个【Star】：

GitHub - PanJinquan/base-utils: 集成C/C++ OpenCV 常用的算法和工具

使用PIP安装：

pip install pybaseutils

【尊重原则，转载请注明出处】https://blog.csdn.net/guyuealian/article/details/128019461

绘制矩形框	绘制多边形

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1. OpenCV鼠标事件操作说明

OpenCV支持鼠标事件操作，通过setMouseCallback函数来设置鼠标事件的回调函数，使用方法可见官方文档说明

（1）setMouseCallback函数说明

void setMousecallback(const string& winname, MouseCallback onMouse, void* userdata=0);
//winname:窗口的名字
//onMouse:鼠标响应函数，回调函数。指定窗口里每次鼠标时间发生的时候，被调用的函数指针。
//这个函数的原型应该为void on_Mouse(int event, int x, int y, int flags, void* param);
//userdate：传给回调函数的参数

（2）回调函数onMouse说明

void onMouse(int event, int x, int y, int flags, void* param);
//event是 CV_EVENT_*变量之一
//x和y是鼠标指针在图像坐标系的坐标（不是窗口坐标系） 
//flags是CV_EVENT_FLAG的组合， param是用户定义的传递到setMouseCallback函数调用的参数。

 

（3）event 具体说明：

EVENT_MOUSEMOVE 0         //滑动
EVENT_LBUTTONDOWN 1  //左键点击
EVENT_RBUTTONDOWN 2  //右键点击
EVENT_MBUTTONDOWN 3  //中键点击
EVENT_LBUTTONUP 4          //左键放开
EVENT_RBUTTONUP 5         //右键放开
EVENT_MBUTTONUP 6          //中键放开
EVENT_LBUTTONDBLCLK 7 //左键双击
EVENT_RBUTTONDBLCLK 8 //右键双击
EVENT_MBUTTONDBLCLK 9 //中键双击

（4）flags 具体说明

EVENT_FLAG_LBUTTON 1   //左键拖曳
EVENT_FLAG_RBUTTON 2   //右键拖曳
EVENT_FLAG_MBUTTON 4   //中键拖曳
EVENT_FLAG_CTRLKEY 8     //(8~15)按 Ctrl 不放
EVENT_FLAG_SHIFTKEY 16 //(16~31)按 Shift 不放
EVENT_FLAG_ALTKEY 32      //(32~39)按 Alt 不放

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2. OpenCV实现鼠标绘制矩形框和多边形

（1）绘制矩形框

这是实现绘制矩形框的关键代码

    def event_draw_rectangle(self, event, x, y, flags, param):"""绘制矩形框"""if len(self.polygons) == 0: self.polygons = np.zeros(shape=(2, 2), dtype=np.int32)  # 多边形轮廓point = (x, y)if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点print("1-EVENT_LBUTTONDOWN")self.next = self.last.copy()self.polygons[0, :] = pointcv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)elif event == cv2.EVENT_MOUSEMOVE and (flags & cv2.EVENT_FLAG_LBUTTON):  # 按住左键拖曳，画框print("2-EVENT_FLAG_LBUTTON")self.next = self.last.copy()cv2.circle(self.next, self.polygons[0, :], radius=4, color=self.focus_color, thickness=self.thickness)cv2.circle(self.next, point, radius=4, color=self.focus_color, thickness=self.thickness)cv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)elif event == cv2.EVENT_LBUTTONUP:  # 左键释放，显示print("3-EVENT_LBUTTONUP")self.next = self.last.copy()self.polygons[1, :] = pointcv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)print("location:{},have:{}".format(point, len(self.polygons)))

（2）绘制多边形

这是实现绘制多边形的关键代码

    def event_draw_polygon(self, event, x, y, flags, param):"""绘制多边形"""exceed = self.max_point > 0 and len(self.polygons) >= self.max_pointself.next = self.last.copy()point = (x, y)text = str(len(self.polygons))if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点print("1-EVENT_LBUTTONDOWN")cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)cv2.putText(self.next, text, point, cv2.FONT_HERSHEY_SIMPLEX, 0.5, self.text_color, 2)if len(self.polygons) > 0:cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)if not exceed:self.last = self.nextself.polygons = np.concatenate([self.polygons, np.array(point).reshape(1, 2)])else:cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)if len(self.polygons) > 0:cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)print("location:{},have:{}".format(point, len(self.polygons)))

（3）键盘控制

为了方便用户操作，这里定义几个常用的按键：

1. 按空格和回车键表示完成绘制
2. 按ESC退出程序
3. 按键盘c重新绘制

    def task(self, image, callback: Callable, winname="winname"):"""鼠标监听任务:param image: 图像:param callback: 鼠标回调函数:param winname: 窗口名称:return:"""self.orig = image.copy()self.last = image.copy()self.next = image.copy()cv2.namedWindow(winname, flags=cv2.WINDOW_NORMAL)cv2.setMouseCallback(winname, callback, param={"winname": winname})while True:self.key = self.show_image(winname, self.next, delay=25)print("key={}".format(self.key))if (self.key == 13 or self.key == 32) and len(self.polygons) > 0:  # 按空格32和回车键13表示完成绘制breakelif self.key == 27:  # ESC退出程序exit(0)elif self.key == 99:  # 按键盘c重新绘制self.clear()# cv2.destroyAllWindows()

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3. 完整的代码

 源码已经开源在GitHub， 开源不易,麻烦给个【Star】：

GitHub - PanJinquan/base-utils: 集成C/C++ OpenCV 常用的算法和工具

使用PIP安装：

pip install pybaseutils

demo测试：base-utils/mouse_utils.py at master · PanJinquan/base-utils · GitHub 

# -*-coding: utf-8 -*-
"""@Author : panjq@E-mail : pan_jinquan@163.com@Date   : 2022-07-27 15:23:24@Brief  :
"""
import cv2
import numpy as np
from typing import Callable
from pybaseutils import image_utilsclass DrawImageMouse(object):"""使用鼠标绘图"""def __init__(self, max_point=-1, line_color=(0, 0, 255), text_color=(255, 0, 0), thickness=2):""":param max_point: 最多绘图的点数，超过后将绘制无效；默认-1表示无限制:param line_color: 线条的颜色:param text_color: 文本的颜色:param thickness: 线条粗细"""self.max_point = max_pointself.line_color = line_colorself.text_color = text_colorself.focus_color = (0, 255, 0)  # 鼠标焦点的颜色self.thickness = thicknessself.key = -1  # 键盘值self.orig = None  # 原始图像self.last = None  # 上一帧self.next = None  # 下一帧或当前帧self.polygons = np.zeros(shape=(0, 2), dtype=np.int32)  # 鼠标绘制点集合def clear(self):self.key = -1self.polygons = np.zeros(shape=(0, 2), dtype=np.int32)if self.orig is not None: self.last = self.orig.copy()if self.orig is not None: self.next = self.orig.copy()def get_polygons(self):"""获得多边形数据"""return self.polygonsdef task(self, image, callback: Callable, winname="winname"):"""鼠标监听任务:param image: 图像:param callback: 鼠标回调函数:param winname: 窗口名称:return:"""self.orig = image.copy()self.last = image.copy()self.next = image.copy()cv2.namedWindow(winname, flags=cv2.WINDOW_NORMAL)cv2.setMouseCallback(winname, callback, param={"winname": winname})while True:self.key = self.show_image(winname, self.next, delay=25)print("key={}".format(self.key))if (self.key == 13 or self.key == 32) and len(self.polygons) > 0:  # 按空格32和回车键13表示完成绘制breakelif self.key == 27:  # 按ESC退出程序exit(0)elif self.key == 99:  # 按键盘c重新绘制self.clear()# cv2.destroyAllWindows()cv2.setMouseCallback(winname, self.event_default)def event_default(self, event, x, y, flags, param):passdef event_draw_rectangle(self, event, x, y, flags, param):"""绘制矩形框"""if len(self.polygons) == 0: self.polygons = np.zeros(shape=(2, 2), dtype=np.int32)  # 多边形轮廓point = (x, y)if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点print("1-EVENT_LBUTTONDOWN")self.next = self.last.copy()self.polygons[0, :] = pointcv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)elif event == cv2.EVENT_MOUSEMOVE and (flags & cv2.EVENT_FLAG_LBUTTON):  # 按住左键拖曳，画框print("2-EVENT_FLAG_LBUTTON")self.next = self.last.copy()cv2.circle(self.next, self.polygons[0, :], radius=4, color=self.focus_color, thickness=self.thickness)cv2.circle(self.next, point, radius=4, color=self.focus_color, thickness=self.thickness)cv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)elif event == cv2.EVENT_LBUTTONUP:  # 左键释放，显示print("3-EVENT_LBUTTONUP")self.next = self.last.copy()self.polygons[1, :] = pointcv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)print("location:{},have:{}".format(point, len(self.polygons)))def event_draw_polygon(self, event, x, y, flags, param):"""绘制多边形"""exceed = self.max_point > 0 and len(self.polygons) >= self.max_pointself.next = self.last.copy()point = (x, y)text = str(len(self.polygons))if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点print("1-EVENT_LBUTTONDOWN")cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)cv2.putText(self.next, text, point, cv2.FONT_HERSHEY_SIMPLEX, 0.5, self.text_color, 2)if len(self.polygons) > 0:cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)if not exceed:self.last = self.nextself.polygons = np.concatenate([self.polygons, np.array(point).reshape(1, 2)])else:cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)if len(self.polygons) > 0:cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)print("location:{},have:{}".format(point, len(self.polygons)))@staticmethoddef polygons2box(polygons):"""将多边形转换为矩形框"""xmin = min(polygons[:, 0])ymin = min(polygons[:, 1])xmax = max(polygons[:, 0])ymax = max(polygons[:, 1])return [xmin, ymin, xmax, ymax]def show_image(self, title, image, delay=5):"""显示图像"""cv2.imshow(title, image)key = cv2.waitKey(delay=delay) if delay >= 0 else -1return keydef draw_image_rectangle_on_mouse(self, image, winname="draw_rectangle"):"""获得鼠标绘制的矩形框box=[xmin,ymin,xmax,ymax]:param image::param winname: 窗口名称:return: box is[xmin,ymin,xmax,ymax]"""self.task(image, callback=self.event_draw_rectangle, winname=winname)polygons = self.get_polygons()box = self.polygons2box(polygons)return boxdef draw_image_polygon_on_mouse(self, image, winname="draw_polygon"):"""获得鼠标绘制的矩形框box=[xmin,ymin,xmax,ymax]:param image::param winname: 窗口名称:return: polygons is (N,2)"""self.task(image, callback=self.event_draw_polygon, winname=winname)polygons = self.get_polygons()return polygonsdef draw_image_rectangle_on_mouse_example(image_file, winname="draw_rectangle"):"""获得鼠标绘制的矩形框:param image_file::param winname: 窗口名称:return: box=[xmin,ymin,xmax,ymax]"""image = cv2.imread(image_file)# 通过鼠标绘制矩形框rectmouse = DrawImageMouse()box = mouse.draw_image_rectangle_on_mouse(image, winname=winname)# 裁剪矩形区域,并绘制最终的矩形框roi: np.ndarray = image[box[1]:box[3], box[0]:box[2]]if roi.size > 0: mouse.show_image("Image ROI", roi)image = image_utils.draw_image_boxes(image, [box], color=(0, 0, 255), thickness=2)mouse.show_image(winname, image, delay=0)return boxdef draw_image_polygon_on_mouse_example(image_file, winname="draw_polygon"):"""获得鼠标绘制的多边形:param image_file::param winname: 窗口名称:return: polygons is (N,2)"""image = cv2.imread(image_file)# 通过鼠标绘制多边形mouse = DrawImageMouse(max_point=-1)polygons = mouse.draw_image_polygon_on_mouse(image, winname=winname)image = image_utils.draw_image_points_lines(image, polygons, thickness=2)mouse.show_image(winname, image, delay=0)return polygonsif __name__ == '__main__':image_file = "../data/test.png"# 绘制矩形框out = draw_image_rectangle_on_mouse_example(image_file)# 绘制多边形out = draw_image_polygon_on_mouse_example(image_file)print(out)

绘制矩形框	绘制多边形