简单的python画图代码_python opencv如何实现简易画图板 python opencv实现简易画图板代码...
python opencv如何实现简易画图板？本篇文章小编给大家分享一下python opencv实现简易画图板代码，小编觉得挺不错的，现在分享给大家供大家参考，有需要的小伙伴们可以来看看。
代码如下：
# -*- coding: utf-8 -*-
"""
Created on Sat May 19 17:34:54 2018
@author: xxx
"""
import cv2 as cv
import numpy as np
def nothing(x):
pass
# 当鼠标按下时变为 True
drawing = False
# 如果 mode 为 True 绘制矩形。按下 'm' 变成绘制曲线
mode = True
ix, iy = -1, -1
#创建回调函数
def draw_circle(event, x, y, flags, param):
r = cv.getTrackbarPos('R', 'image')
g = cv.getTrackbarPos('G', 'image')
b = cv.getTrackbarPos('B', 'image')
color = (b, g, r)
global ix, iy, drawing, mode
# 当按下左键是返回起始位置坐标
if event == cv.EVENT_LBUTTONDOWN:
drawing = True
ix, iy = x, y
# 当鼠标左键按下并移动是绘制图形。event 可以查看移动, flag 查看是否按下
elif event == cv.EVENT_MOUSEMOVE and flags == cv.EVENT_FLAG_LBUTTON:
if drawing == True:
if mode == True:
cv.rectangle(img, (ix, iy), (x, y), color, -1)
else:
# 绘制圆圈，小圆点连在一起就成了线，3代表画笔的粗细
cv.circle(img, (ix, iy), 3, color, -1)
# 下面注释的代码是起始点为圆心，起点到终点为半径
# r = int(np.sqrt((x - ix)**2 + (y - iy)**2))
# cv.circle(img, (x, y), r, (0, 0, 255), -1)
# 当鼠标松开停止绘画
elif event == cv.EVENT_LBUTTONUP:
drawing == False
# if mode == True:
# cv.rectangle(img, (ix, iy), (x, y), (0, 255, 0), -1)
# else:
# cv.circle(img, (x, y), 5, (0, 0, 255), -1)
#创建一幅黑色图形
img = np.zeros((512, 512, 3), np.uint8)
cv.namedWindow('image')
cv.createTrackbar('R', 'image', 0, 255, nothing)
cv.createTrackbar('G', 'image', 0, 255, nothing)
cv.createTrackbar('B', 'image', 0, 255, nothing)
cv.setMouseCallback('image', draw_circle)
while(1):
cv.imshow('image', img)
k = cv.waitKey(1)&0xFF
if k == ord('m'):
mode = not mode
elif k==27:
break
cv.destroyAllWindow()