• Python OpenCV实现鼠标绘制矩形框和多边形

    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

    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

    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

    1. void setMousecallback(const string& winname, MouseCallback onMouse, void* userdata=0);
    2. //winname:窗口的名字
    3. //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。
    4. //这个函数的原型应该为void on_Mouse(int event, int x, int y, int flags, void* param);
    5. //userdate：传给回调函数的参数

    （2）回调函数onMouse说明

    1.  
    2. void onMouse(int event, int x, int y, int flags, void* param);
    3. //event是 CV_EVENT_*变量之一
    4. //x和y是鼠标指针在图像坐标系的坐标（不是窗口坐标系） 
    5. //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

    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

    1.     def event_draw_rectangle(self, event, x, y, flags, param):
    2.         """绘制矩形框"""
    3.         if len(self.polygons) == 0: self.polygons = np.zeros(shape=(2, 2), dtype=np.int32)  # 多边形轮廓
    4.         point = (x, y)
    5.         if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点
    6.             print("1-EVENT_LBUTTONDOWN")
    7.             self.next = self.last.copy()
    8.             self.polygons[0, :] = point
    9.             cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)
    10.         elif event == cv2.EVENT_MOUSEMOVE and (flags & cv2.EVENT_FLAG_LBUTTON):  # 按住左键拖曳，画框
    11.             print("2-EVENT_FLAG_LBUTTON")
    12.             self.next = self.last.copy()
    13.             cv2.circle(self.next, self.polygons[0, :], radius=4, color=self.focus_color, thickness=self.thickness)
    14.             cv2.circle(self.next, point, radius=4, color=self.focus_color, thickness=self.thickness)
    15.             cv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)
    16.         elif event == cv2.EVENT_LBUTTONUP:  # 左键释放，显示
    17.             print("3-EVENT_LBUTTONUP")
    18.             self.next = self.last.copy()
    19.             self.polygons[1, :] = point
    20.             cv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)
    21.         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

    1.     def event_draw_polygon(self, event, x, y, flags, param):
    2.         """绘制多边形"""
    3.         exceed = self.max_point > 0 and len(self.polygons) >= self.max_point
    4.         self.next = self.last.copy()
    5.         point = (x, y)
    6.         text = str(len(self.polygons))
    7.         if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点
    8.             print("1-EVENT_LBUTTONDOWN")
    9.             cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)
    10.             cv2.putText(self.next, text, point, cv2.FONT_HERSHEY_SIMPLEX, 0.5, self.text_color, 2)
    11.             if len(self.polygons) > 0:
    12.                 cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)
    13.             if not exceed:
    14.                 self.last = self.next
    15.                 self.polygons = np.concatenate([self.polygons, np.array(point).reshape(1, 2)])
    16.         else:
    17.             cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)
    18.             if len(self.polygons) > 0:
    19.                 cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)
    20.         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
    1.     def task(self, image, callback: Callable, winname="winname"):
    2.         """
    3.         鼠标监听任务
    4.         :param image: 图像
    5.         :param callback: 鼠标回调函数
    6.         :param winname: 窗口名称
    7.         :return:
    8.         """
    9.         self.orig = image.copy()
    10.         self.last = image.copy()
    11.         self.next = image.copy()
    12.         cv2.namedWindow(winname, flags=cv2.WINDOW_NORMAL)
    13.         cv2.setMouseCallback(winname, callback, param={"winname": winname})
    14.         while True:
    15.             self.key = self.show_image(winname, self.next, delay=25)
    16.             print("key={}".format(self.key))
    17.             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
    18.                 break
    19.             elif self.key == 27:  # ESC退出程序
    20.                 exit(0)
    21.             elif self.key == 99:  # 按键盘c重新绘制
    22.                 self.clear()
    23.         # cv2.destroyAllWindows()

    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

    1. # -*-coding: utf-8 -*-
    2. """
    3.     @Author : panjq
    4.     @E-mail : pan_jinquan@163.com
    5.     @Date   : 2022-07-27 15:23:24
    6.     @Brief  :
    7. """
    8. import cv2
    9. import numpy as np
    10. from typing import Callable
    11. from pybaseutils import image_utils
    12.  
    13.  
    14. class DrawImageMouse(object):
    15.     """使用鼠标绘图"""
    16.  
    17.     def __init__(self, max_point=-1, line_color=(0, 0, 255), text_color=(255, 0, 0), thickness=2):
    18.         """
    19.         :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
    20.         :param line_color: 线条的颜色
    21.         :param text_color: 文本的颜色
    22.         :param thickness: 线条粗细
    23.         """
    24.         self.max_point = max_point
    25.         self.line_color = line_color
    26.         self.text_color = text_color
    27.         self.focus_color = (0, 255, 0)  # 鼠标焦点的颜色
    28.         self.thickness = thickness
    29.         self.key = -1  # 键盘值
    30.         self.orig = None  # 原始图像
    31.         self.last = None  # 上一帧
    32.         self.next = None  # 下一帧或当前帧
    33.         self.polygons = np.zeros(shape=(0, 2), dtype=np.int32)  # 鼠标绘制点集合
    34.  
    35.     def clear(self):
    36.         self.key = -1
    37.         self.polygons = np.zeros(shape=(0, 2), dtype=np.int32)
    38.         if self.orig is not None: self.last = self.orig.copy()
    39.         if self.orig is not None: self.next = self.orig.copy()
    40.  
    41.     def get_polygons(self):
    42.         """获得多边形数据"""
    43.         return self.polygons
    44.  
    45.     def task(self, image, callback: Callable, winname="winname"):
    46.         """
    47.         鼠标监听任务
    48.         :param image: 图像
    49.         :param callback: 鼠标回调函数
    50.         :param winname: 窗口名称
    51.         :return:
    52.         """
    53.         self.orig = image.copy()
    54.         self.last = image.copy()
    55.         self.next = image.copy()
    56.         cv2.namedWindow(winname, flags=cv2.WINDOW_NORMAL)
    57.         cv2.setMouseCallback(winname, callback, param={"winname": winname})
    58.         while True:
    59.             self.key = self.show_image(winname, self.next, delay=25)
    60.             print("key={}".format(self.key))
    61.             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
    62.                 break
    63.             elif self.key == 27:  # 按ESC退出程序
    64.                 exit(0)
    65.             elif self.key == 99:  # 按键盘c重新绘制
    66.                 self.clear()
    67.         # cv2.destroyAllWindows()
    68.         cv2.setMouseCallback(winname, self.event_default)
    69.  
    70.     def event_default(self, event, x, y, flags, param):
    71.         pass
    72.  
    73.     def event_draw_rectangle(self, event, x, y, flags, param):
    74.         """绘制矩形框"""
    75.         if len(self.polygons) == 0: self.polygons = np.zeros(shape=(2, 2), dtype=np.int32)  # 多边形轮廓
    76.         point = (x, y)
    77.         if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点
    78.             print("1-EVENT_LBUTTONDOWN")
    79.             self.next = self.last.copy()
    80.             self.polygons[0, :] = point
    81.             cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)
    82.         elif event == cv2.EVENT_MOUSEMOVE and (flags & cv2.EVENT_FLAG_LBUTTON):  # 按住左键拖曳，画框
    83.             print("2-EVENT_FLAG_LBUTTON")
    84.             self.next = self.last.copy()
    85.             cv2.circle(self.next, self.polygons[0, :], radius=4, color=self.focus_color, thickness=self.thickness)
    86.             cv2.circle(self.next, point, radius=4, color=self.focus_color, thickness=self.thickness)
    87.             cv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)
    88.         elif event == cv2.EVENT_LBUTTONUP:  # 左键释放，显示
    89.             print("3-EVENT_LBUTTONUP")
    90.             self.next = self.last.copy()
    91.             self.polygons[1, :] = point
    92.             cv2.rectangle(self.next, self.polygons[0, :], point, color=self.line_color, thickness=self.thickness)
    93.         print("location:{},have:{}".format(point, len(self.polygons)))
    94.  
    95.     def event_draw_polygon(self, event, x, y, flags, param):
    96.         """绘制多边形"""
    97.         exceed = self.max_point > 0 and len(self.polygons) >= self.max_point
    98.         self.next = self.last.copy()
    99.         point = (x, y)
    100.         text = str(len(self.polygons))
    101.         if event == cv2.EVENT_LBUTTONDOWN:  # 左键点击,则在原图打点
    102.             print("1-EVENT_LBUTTONDOWN")
    103.             cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)
    104.             cv2.putText(self.next, text, point, cv2.FONT_HERSHEY_SIMPLEX, 0.5, self.text_color, 2)
    105.             if len(self.polygons) > 0:
    106.                 cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)
    107.             if not exceed:
    108.                 self.last = self.next
    109.                 self.polygons = np.concatenate([self.polygons, np.array(point).reshape(1, 2)])
    110.         else:
    111.             cv2.circle(self.next, point, radius=5, color=self.focus_color, thickness=self.thickness)
    112.             if len(self.polygons) > 0:
    113.                 cv2.line(self.next, self.polygons[-1, :], point, color=self.line_color, thickness=self.thickness)
    114.         print("location:{},have:{}".format(point, len(self.polygons)))
    115.  
    116.     @staticmethod
    117.     def polygons2box(polygons):
    118.         """将多边形转换为矩形框"""
    119.         xmin = min(polygons[:, 0])
    120.         ymin = min(polygons[:, 1])
    121.         xmax = max(polygons[:, 0])
    122.         ymax = max(polygons[:, 1])
    123.         return [xmin, ymin, xmax, ymax]
    124.  
    125.     def show_image(self, title, image, delay=5):
    126.         """显示图像"""
    127.         cv2.imshow(title, image)
    128.         key = cv2.waitKey(delay=delay) if delay >= 0 else -1
    129.         return key
    130.  
    131.     def draw_image_rectangle_on_mouse(self, image, winname="draw_rectangle"):
    132.         """
    133.         获得鼠标绘制的矩形框box=[xmin,ymin,xmax,ymax]
    134.         :param image:
    135.         :param winname: 窗口名称
    136.         :return: box is[xmin,ymin,xmax,ymax]
    137.         """
    138.         self.task(image, callback=self.event_draw_rectangle, winname=winname)
    139.         polygons = self.get_polygons()
    140.         box = self.polygons2box(polygons)
    141.         return box
    142.  
    143.     def draw_image_polygon_on_mouse(self, image, winname="draw_polygon"):
    144.         """
    145.         获得鼠标绘制的矩形框box=[xmin,ymin,xmax,ymax]
    146.         :param image:
    147.         :param winname: 窗口名称
    148.         :return: polygons is (N,2)
    149.         """
    150.         self.task(image, callback=self.event_draw_polygon, winname=winname)
    151.         polygons = self.get_polygons()
    152.         return polygons
    153.  
    154.  
    155. def draw_image_rectangle_on_mouse_example(image_file, winname="draw_rectangle"):
    156.     """
    157.     获得鼠标绘制的矩形框
    158.     :param image_file:
    159.     :param winname: 窗口名称
    160.     :return: box=[xmin,ymin,xmax,ymax]
    161.     """
    162.     image = cv2.imread(image_file)
    163.     # 通过鼠标绘制矩形框rect
    164.     mouse = DrawImageMouse()
    165.     box = mouse.draw_image_rectangle_on_mouse(image, winname=winname)
    166.     # 裁剪矩形区域,并绘制最终的矩形框
    167.     roi: np.ndarray = image[box[1]:box[3], box[0]:box[2]]
    168.     if roi.size > 0: mouse.show_image("Image ROI", roi)
    169.     image = image_utils.draw_image_boxes(image, [box], color=(0, 0, 255), thickness=2)
    170.     mouse.show_image(winname, image, delay=0)
    171.     return box
    172.  
    173.  
    174. def draw_image_polygon_on_mouse_example(image_file, winname="draw_polygon"):
    175.     """
    176.     获得鼠标绘制的多边形
    177.     :param image_file:
    178.     :param winname: 窗口名称
    179.     :return: polygons is (N,2)
    180.     """
    181.     image = cv2.imread(image_file)
    182.     # 通过鼠标绘制多边形
    183.     mouse = DrawImageMouse(max_point=-1)
    184.     polygons = mouse.draw_image_polygon_on_mouse(image, winname=winname)
    185.     image = image_utils.draw_image_points_lines(image, polygons, thickness=2)
    186.     mouse.show_image(winname, image, delay=0)
    187.     return polygons
    188.  
    189.  
    190. if __name__ == '__main__':
    191.     image_file = "../data/test.png"
    192.     # 绘制矩形框
    193.     out = draw_image_rectangle_on_mouse_example(image_file)
    194.     # 绘制多边形
    195.     out = draw_image_polygon_on_mouse_example(image_file)
    196.     print(out)
     绘制矩形框绘制多边形

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  • 原文地址：https://blog.csdn.net/guyuealian/article/details/128019461