9.2 用OpenCV-Python操作图像

# -*- coding:utf8 -*-
import cv2
import numpy as np

#加载并显示图像
image_file2 = 'image/2.jpg'
image_91 = cv2.imread(image_file2)
# cv2.imread() 读取的是 numpy.array的数组
cv2.imshow('image_91',image_91)

#裁剪图像
h,w = image_91.shape[:2]
start_row,end_row = int(0.1*h),int(0.8*h)
start_col,end_col = int(0.1*w),int(0.8*w)

# cv2.imread() 读取的是 numpy.array的数组  所以可以用分片
image_91_cropped = image_91[start_row:end_row,start_col:end_col]
cv2.imshow('image_91_cropped',image_91_cropped)

#调整图片大小
scaling_fector = 1.3
image_91_scaled = cv2.resize(image_91,None,fx=scaling_fector,fy=scaling_fector,interpolation=cv2.INTER_LINEAR)
cv2.imshow('image_91_scaled',image_91_scaled)

#一个维度的扩展
image_91_scaled_1 = cv2.resize(image_91,(150,400),interpolation=cv2.INTER_AREA)
cv2.imshow('image_91_scaled_1',image_91_scaled_1)

#保存为输出文件
output_file = image_file2[:-4] + '_cropped.jpg'
cv2.imwrite(output_file,image_91_cropped)

cv2.waitKey(0)

原图：

image.png

裁剪图像

image.png

放大图像

image.png

在一个维度上扩展图像

image.png

保存后的截图

image.png

'''