opencv 图片缩放

 1 import cv2 as cv
 2 import numpy as np
 3 
 4 # 图片缩放
 5 img = cv.imread('../images/moon.jpg', flags=1)  # flags=1读取为彩色，flags=0读取为灰度
 6 cv.imshow('i', img)
 7 h, w, channel = img.shape  # 以行列形式存储, 第几行到第几行为图像高度
 8 dst_h = int(h*0.5)
 9 dst_w = int(w*0.5)
10 # 最近邻域差值 双线性插值 像素关系重采样 立方差值
11 dst = cv.resize(img, (dst_w, dst_h))  # 默认双线性差值
12 cv.imshow('img', dst)
13 cv.waitKey(0)

关于这几个差值

https://blog.youkuaiyun.com/woainishifu/article/details/53260546

 

通过矩阵变换进行缩放

 

 1 import cv2 as cv
 2 import numpy as np
 3 
 4 # 图片缩放
 5 img = cv.imread('../images/moon.jpg', flags=1)  # flags=1读取为彩色，flags=0读取为灰度
 6 h, w = img.shape[:2]
 7 mat_shift = np.float32([[0.5, 0, 0], [0, 0.5, 0]])  # 缩放矩阵
 8 dst = cv.warpAffine(img, mat_shift, (int(w/2), int(h/2)))
 9 cv.imshow('img1', img)
10 cv.imshow('img2', dst)
11 cv.waitKey(0)

 

转载于:https://www.cnblogs.com/MC-Curry/p/10408575.html