Python-OpenCV 杂项（一）：图像绘制

我就是我 2022-07-14 13:38 170阅读 0赞

# Python-OpenCV 杂项（一）：图像绘制 #

[![RJKWONG][]][RJKWONG 1]

#### [RJKWONG][RJKWONG 1] ####

发表于 2015-09-30 10:28:46

### 0x00. 绘制直线 ###

import numpy as np
    import cv2
    img = np.zeros((512,512,3), np.uint8)
    
    cv2.line(img,(0,0),(511,511),(255,0,0),5)
    cv2.imshow('image',img)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

### 0x01. 绘制矩形 ###

cv2.rectangle(img,(384,0),(510,128),(0,255,0),3)

### 0x02. 画圆 ###

cv2.circle(img,(447,63), 63, (0,0,255), -1)

### 0x03. 画椭圆 ###

cv2.ellipse(img,(256,256),(100,50),0,0,180,255,-1)

### 0x04. 绘制多边形 ###

pts = np.array([[10,5],[20,30],[70,20],[50,10]], np.int32)
    pts = pts.reshape((-1,1,2))
    img = cv2.polylines(img,[pts],True,(0,255,255))

### 0x05. 添加文本 ###

font = cv2.FONT_HERSHEY_SIMPLEX
    cv2.putText(img,'OpenCV',(10,500), font, 4,(255,255,255),2,cv2.LINE_AA)

### 0x06. 一个调色板 ###

import cv2
    import numpy as np
    
    def nothing(x):
    pass
    
    # Create a black image, a window
    img = np.zeros((300,512,3), np.uint8)
    cv2.namedWindow('image')
    
    # create trackbars for color change
    cv2.createTrackbar('R','image',0,255,nothing)
    cv2.createTrackbar('G','image',0,255,nothing)
    cv2.createTrackbar('B','image',0,255,nothing)
    
    # create switch for ON/OFF functionality
    switch = '0 : OFF n1 : ON'
    cv2.createTrackbar(switch, 'image',0,1,nothing)
    
    while(1):
    cv2.imshow('image',img)
     k = cv2.waitKey(1) & 0xFF
     if k == 27:
    break
    
     # get current positions of four trackbars
     r = cv2.getTrackbarPos('R','image')
     g = cv2.getTrackbarPos('G','image')
     b = cv2.getTrackbarPos('B','image')
     s = cv2.getTrackbarPos(switch,'image')
    
     if s == 0:
     img[:] = 0
    else:
     img[:] = [b,g,r]
    
    cv2.destroyAllWindows()

*  [上一个： Python-OpenCV 杂项（二）： 鼠标事件][Python-OpenCV _]
 *  [下一个： Python-OpenCV 处理视频（五）： 运动方向判断][Python-OpenCV _ 1]

[RJKWONG]: http://www.thinksaas.cn/cache/user/0/26/120/26009.jpg
[RJKWONG 1]: http://www.thinksaas.cn/user/space/26009/
[Python-OpenCV _]: http://www.thinksaas.cn/topics/0/395/395932.html
[Python-OpenCV _ 1]: http://www.thinksaas.cn/topics/0/395/395934.html