python opencv

目录

• 1.画图
• 3.roi区域
• 4. 批量resize
• 5. cv2.copyMakeBorder

1.画图

import cv2
import numpy as np
def drew():
    pic = np.zeros([512, 512, 3])	#定义一个像素长宽分别为512/512，通道为3层的画布
    
    # 直线（参数分别为：画布名称，起点坐标，终点坐标，颜色，线宽）
    cv2.line(pic, (256, 512), (256, 0), (255, 255, 0), 4)  
    
    # 矩形（参数分别为：画布名称，左上角坐标，右下角坐标，颜色，线宽）
    cv2.rectangle(pic, (128, 384), (384, 128), (0, 255, 255), 4)

    # 圆（参数分别为：画布名称，圆心坐标，半径，颜色，线宽）
    cv2.circle(pic, (256, 256), 50, (250, 250, 250), 4)  

 	# 椭圆（参数分别为：画布名称，圆心坐标，（长半径，短半径），逆时针旋转角度，逆时针开始画图的角度， 逆时针结束画图角度，颜色，线宽）
    cv2.ellipse(pic, (256, 256), (128, 64), 90, 0, 360, (255, 0, 255), 4) 

	#多边形
    ply = np.array([[50, 190], [380, 420], [255, 50], [120, 420], [450, 190]])  # 注：像素数组
    cv2.polylines(pic, [ply], True, (200, 100, 0), 4)  # 多边形（像素数组，是否封口）

	#文字
    cv2.putText(pic, 'this is change', (128, 450), cv2.FONT_HERSHEY_SIMPLEX, 1.6, (100, 100, 100), 2)  # 文字（text,起始坐标，字体，文字大小，颜色，线宽）
    cv2.namedWindow('line')
    cv2.imshow('line', pic)
    cv2.waitKey(0)
    cv2.destroyWindow('line')

#   像素赋值
def white(img, numbers):
    for i in range(numbers):
        for j in range(numbers):
            for k in range(3):
                img[i][j][k] = 255
    return img

#   椒盐函数
def salt(img, numbers):
    for x in range(numbers):
        i = np.random.randint(img.shape[0])
        j = np.random.randint(img.shape[1])
        for k in range(3):
            img[i][j][k] = 255
    return img
import os
import cv2

root = "/media/data_2/everyday/0807/20190806/"
save_path = os.path.dirname(os.path.dirname(root)) + '/root_new/'

if not os.path.exists(save_path):
    os.makedirs(save_path)

new_size = 1280

list_file = os.listdir(root)
for cnt,img_name in enumerate(list_file):
    print("cnt=%d,img=%s"%(cnt,img_name))
    img_path = root + img_name
    img = cv2.imread(img_path)
    img_new = cv2.resize(img,(new_size,new_size))
    cv2.imwrite(save_path + img_name,img_new)
#   通道分离
def conduit(img):

    b, g, r = cv2.split(img)
    pic = np.zeros(np.shape(img), np.uint8)  # 像素清零
    pic[:, :, 0] = b
    cv2.namedWindow('Blue')
    cv2.imshow('Blue', pic)
    cv2.waitKey(0)

    pic[:, :, 1] = g
    cv2.namedWindow('Green')
    cv2.imshow('Green', pic)
    cv2.waitKey(0)

    pic[:, :, 2] = r
    cv2.namedWindow('Red')
    cv2.imshow('Red', pic)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

#   通道合并
def merge(b, g, r):
    m = cv2.merge([b, g, r])    # cv2自带通道合并方法
    dstack = np.dstack([b, g, import os
import cv2

root = "/media/data_2/everyday/0807/20190806/"
save_path = os.path.dirname(os.path.dirname(root)) + '/root_new/'

if not os.path.exists(save_path):
    os.makedirs(save_path)

new_size = 1280

list_file = os.listdir(root)
for cnt,img_name in enumerate(list_file):
    print("cnt=%d,img=%s"%(cnt,img_name))
    img_path = root + img_name
    img = cv2.imread(img_path)
    img_new = cv2.resize(img,(new_size,new_size))
    cv2.imwrite(save_path + img_name,img_new)r])    # np的dstack

3.roi区域

m_roi = img[0:img.shape[0],x1:x1+w1]

4. 批量resize

import os
import cv2

root = "/media/data_2/everyday/0807/20190806/"
save_path = os.path.dirname(os.path.dirname(root)) + '/root_new/'

if not os.path.exists(save_path):
    os.makedirs(save_path)

new_size = 1280

list_file = os.listdir(root)
for cnt,img_name in enumerate(list_file):
    print("cnt=%d,img=%s"%(cnt,img_name))
    img_path = root + img_name
    img = cv2.imread(img_path)
    img_new = cv2.resize(img,(new_size,new_size))
    cv2.imwrite(save_path + img_name,img_new)

5. cv2.copyMakeBorder

import cv2

img = cv2.imread("/data_2/part-00729-3292.jpg")
######cv2.copyMakeBorder(img, top, bottem, left, right, cv2.BORDER_REPLICATE)
# img2 = cv2.copyMakeBorder(img,300,400,20,100,cv2.BORDER_REPLICATE)
img2 = cv2.copyMakeBorder(img,300,400,500,400,cv2.BORDER_CONSTANT,value=(127,127,127))

cv2.namedWindow("img",0)
cv2.namedWindow("img2",0)
cv2.imshow("img",img)
cv2.imshow("img2",img2)
cv2.waitKey()