图片感兴趣区域ROI获取——鼠标选择矩阵区域+不规则多边形区域（anoconda3.4+spyder+python3.5+opencv3.4）
一.python+OpenCV 鼠标交互图片切割矩形区域【转载】
https://www.jianshu.com/p/5f7df3d8b237
# -*- coding: utf-8 -*-
"""
Created on Mon Jun 25 22:22:42 2018
"""
#----------------------------------------------------------
#作者：庞贝船长
#链接：https://www.jianshu.com/p/5f7df3d8b237
#來源：简书
#简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。
#-------------------------------------------------
import cv2
global img
global point1, point2
def on_mouse(event, x, y, flags, param):
global img, point1, point2
img2 = img.copy()
if event == cv2.EVENT_LBUTTONDOWN: #左键点击
point1 = (x,y)
cv2.circle(img2, point1, 10, (0,255,0), 5)
cv2.imshow('src', img2)
elif event == cv2.EVENT_MOUSEMOVE and (flags & cv2.EVENT_FLAG_LBUTTON): #按住左键拖曳
cv2.rectangle(img2, point1, (x,y), (255,0,0), 5)
cv2.imshow('src', img2)
elif event == cv2.EVENT_LBUTTONUP: #左键释放
point2 = (x,y)
cv2.rectangle(img2, point1, point2, (0,0,255), 5)
cv2.imshow('src', img2)
min_x = min(point1[0],point2[0])
min_y = min(point1[1],point2[1])
width = abs(point1[0] - point2[0])
height = abs(point1[1] -point2[1])
cut_img = img[min_y:min_y+height, min_x:min_x+width]
cv2.imshow('ROI_rectangle', cut_img)
def main():
global img
img = cv2.imread('frame_0.5.bmp')
cv2.namedWindow('src')
cv2.setMouseCallback('src', on_mouse)
cv2.imshow('src', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
if __name__ == '__main__':
main()
二、鼠标点击选取不规则多边形感兴趣区域【自己整理】
【参考博文】：
0.【链接】python get non-rectangular region from stackoverflow
1.【链接】使用python绘制各种图形（线，矩形，圆，多边形，添加文字等）
2.【链接】使用c++，fillPoly函数填充多边形
3.【链接】使用python实现掩膜功能，即抠图
4.【链接】Python在函数中使用全局变量的问题
5.【链接】c++固定点截取ROI区域
6.【链接】c++ 选取roi区域（矩形，不规则多边形，圆形，椭圆，手动指定形状）
【其中全局变量使用有点混乱，这只是代码的一部分，细节未删除，还请大家随便看看】
# -*- coding: utf-8 -*-
"""
Created on Sat Jun 23 15:16:16 2018
@author: Zengxy_GUET
"""
import cv2
import numpy as np
global img
global point1, point2
lsPointsChoose=[]
tpPointsChoose=[]
pointsCount=0
count=0
pointsMax=5
#-----------------------鼠标操作相关------------------------------------------
#------------------------------------------------------------------------------
lsPointsChoose=[]
tpPointsChoose=[]
pointsCount=0
count=0
pointsMax=5
def on_mouse(event, x, y, flags, param):
global img, point1, point2,count,pointsMax
global lsPointsChoose,tpPointsChoose #存入选择的点
global pointsCount #对鼠标按下的点计数
global img2,ROI_bymouse_flag
img2 = img.copy() #此行代码保证每次都重新再原图画 避免画多了
#-----------------------------------------------------------
# count=count+1
# print("callback_count",count)
#--------------------------------------------------------------
if event == cv2.EVENT_LBUTTONDOWN: #左键点击
pointsCount=pointsCount+1
# 为了保存绘制的区域，画的点稍晚清零
if(pointsCount==pointsMax+1):
pointsCount=0
tpPointsChoose=[]
print('pointsCount:',pointsCount)
point1 = (x,y)
print (x,y)
# 画出点击的点
cv2.circle(img2, point1, 10, (0,255,0), 5)
# 将选取的点保存到list列表里
lsPointsChoose.append([x,y]) #用于转化为darry 提取多边形ROI
tpPointsChoose.append((x,y)) #用于画点
#----------------------------------------------------------------------
#将鼠标选的点用直线链接起来
print(len(tpPointsChoose))
for i in range(len(tpPointsChoose)-1):
print('i',i)
cv2.line(img2,tpPointsChoose[i],tpPointsChoose[i+1],(0,0,255),5)
#----------------------------------------------------------------------
#----------点击到pointMax时可以提取去绘图----------------
if(pointsCount==pointsMax):
#-----------绘制感兴趣区域-----------
#----------------------------------
ROI_byMouse()
ROI_bymouse_flag=1
lsPointsChoose=[]
#--------------------------------------------------------
cv2.imshow('src', img2)
#-------------------------右键按下清除轨迹-----------------------------
if event == cv2.EVENT_RBUTTONDOWN: #右键点击
print("right-mouse")
pointsCount=0
tpPointsChoose=[]
lsPointsChoose=[]
print(len(tpPointsChoose))
for i in range(len(tpPointsChoose)-1):
print('i',i)
cv2.line(img2,tpPointsChoose[i],tpPointsChoose[i+1],(0,0,255),5)
cv2.imshow('src', img2)
#-----------------------------------------------------------------------
#%%
#--------------------------------------------------------------
def ROI_byMouse():
global src,ROI,ROI_flag,mask2
mask = np.zeros(img.shape, np.uint8)
pts = np.array([lsPointsChoose], np.int32)
# pts.shape=(4，2)
pts = pts.reshape((-1,1,2)) # -1代表剩下的维度自动计算
# reshape 后的 pts.shape=(4。1，2)？？
#--------------画多边形---------------------
mask = cv2.polylines(mask,[pts],True,(0,255,255))
##-------------填充多边形---------------------
mask2=cv2.fillPoly(mask, [pts], (255,255,255))
cv2.imshow('mask',mask2)
# cv2.imwrite('mask20624.bmp',mask2 )
ROI= cv2.bitwise_and(mask2,img)
# cv2.imwrite('ROI0624.bmp',ROI)
cv2.imshow('ROI', ROI)
#-----------------------定点ROI绘制，程序中未使用-------------------
def fixed_ROI():
mask = np.zeros(img.shape, np.uint8)
pts = np.array([[347, 190],[495, 185],[1120,600],[575,649]], np.int32)
# pts.shape=(4，2)
pts = pts.reshape((-1,1,2)) # -1代表剩下的维度自动计算
# reshape 后的 pts.shape=(4。1，2)？？
mask = cv2.polylines(mask,[pts],True,(0,255,255))
mask2=cv2.fillPoly(mask, [pts], (255,255,255))
cv2.imshow('mask',mask2)
cv2.imwrite('mask0623.bmp',mask2 )
# cv2.drawContours(mask,points,-1,(255,255,255),-1)
#-----anwei
ROI= cv2.bitwise_and(mask2,img)
cv2.imshow('ROI',ROI)
cv2.imwrite('ROI0623.bmp',ROI)
def main():
global img,img2,ROI
img = cv2.imread('frame_1.bmp')
#---------------------------------------------------------
#--图像预处理，设置其大小
height, width = img.shape[:2]
size = (int(width*0.3), int(height*0.3))
img=cv2.resize(img,size, interpolation=cv2.INTER_AREA)
#------------------------------------------------------------
ROI = img.copy()
cv2.namedWindow('src')
cv2.setMouseCallback('src', on_mouse)
cv2.imshow('src', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
if __name__ == '__main__':
main()