Python之opencv画图

1.安装opencv

pip install opencv-python

2.简单举例

(1)具体代码如下

import cv2
import numpy as np
# (400, 300, 3):高度,宽度,维数
img_array = np.zeros((400, 300, 3))
# 蓝绿红
img_array[100][200] = (255, 0, 0)
cv2.imshow('black', img_array)
cv2.waitKey(0)
cv2.destroyAllWindows()

效果如下:

(2) 具体代码如下

import cv2
import numpy as np

black_arraty= np.zeros((100, 150, 3), dtype=np.uint8)
for x in range(100):
    for y in range(150):
        if x <= 100//3:
            black_arraty[x][y] = (0, 0, 255)
        elif x <= 2*100//3:
            black_arraty[x][y] = (0, 255, 0)
        else:
            black_arraty[x][y] = (255, 0, 0)
cv2.imshow('红绿蓝', black_arraty)
cv2.waitKey(0)
cv2.destroyAllWindows()

效果如下:

(3) 读取已有图片

具体代码如下:

import cv2
img = cv2.imread("a.jpg")
cv2.imshow("abc",img)
cv2.waitKey(0)
cv2.destroyAllWindows()

a.jpg如下:

效果图如下: