Opencv从入门到精通（三）：图像基础操作和变形与裁剪

文章目录

一、基础操作

在Opencv中约定通道是BGR
但是彩色图像是RGB

img = cv2.imread('./1.png')# print(img, type(img))  # ndarray

img_gray = cv2.cvtColor(img, code=cv2.COLOR_BGR2GRAY)# 转成灰色图
img_blur = cv2.GaussianBlur(img_gray, ksize=(7,7), sigmaX=0)# 让图像变模糊 ksize 参数必须是奇数

img_canny = cv2.Canny(img_gray,150,100)# 边缘检测import numpy as np

kernel = np.ones(shape=(5,5), dtype=np.uint8)# np.uint8: 0-255
img_dialation = cv2.dilate(img_canny, kernel, iterations=1)# 让图像变厚
img_eroded = cv2.erode(img_dialation, kernel, iterations=1)# 腐蚀图像 让图像变薄print(img_gray)
cv2.imshow('Gray Image', img_gray)
cv2.imshow('Blur Image', img_blur)
cv2.imshow('Canny Image', img_canny)
cv2.imshow('Dialation Image', img_dialation)
cv2.imshow('Eroded Image', img_eroded)
cv2.waitKey(0)

二、resize和crop

# 变形 cv2.resize(src,dsize)import cv2

img = cv2.imread('1.png')print(img.shape)# (136, 102, 3)

img_resize = cv2.resize(img, dsize=(300,300))# H*W*C(BGR)print(img_resize.shape)# (300, 300, 3)
cv2.imshow('Img', img)

cv2.imshow('Img Resize', img_resize)
cv2.waitKey(0)

# 裁剪 就是ndaryy切片import cv2

img = cv2.imread('1.png')
cv2.imshow('Img', img)

img_crop = img[1:100]

cv2.imshow('Img Crop', img_crop)
cv2.waitKey(0)