Python OpenCV实现鼠标绘制矩形框和多边形
目录
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】：
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
-
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
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, :] = point
-
cv2.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, :] = point
-
cv2.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_point
-
self.
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.
next
-
self.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：
- 按空格和回车键表示完成绘制
- 按ESC退出程序
- 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
-
break
-
elif 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()
3. 完整的代码
源码已经开源在GitHub， 开源不易,麻烦给个【Star】：
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_utils
-
-
-
class
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_point
-
self.line_color = line_color
-
self.text_color = text_color
-
self.focus_color = (
0,
255,
0)
# 鼠标焦点的颜色
-
self.thickness = thickness
-
self.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 = -
1
-
self.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.polygons
-
-
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
-
break
-
elif 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):
-
pass
-
-
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, :] = point
-
cv2.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, :] = point
-
cv2.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_point
-
self.
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.
next
-
self.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)))
-
-
@staticmethod
-
def
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 -
1
-
return key
-
-
def
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 box
-
-
def
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 polygons
-
-
-
def
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rect
-
mouse = 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 box
-
-
-
def
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 polygons
-
-
-
if __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 |
|
|
转载：https://blog.csdn.net/guyuealian/article/details/128019461
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