How to modify image resolution size in python

Python changes the image resolution size

Image resolution refers to the amount of information stored in the image, which is the number of pixels per inch of the image. The unit of resolution is PPI (Pixels Per Inch). Usually It's called pixels per inch. Image resolution is generally used in PS to change the clarity of the image.

The size of the image resolution will affect the progress of our experiment. Modifying the appropriate resolution can allow the experiment to proceed perfectly.

The resolution of the image can be adjusted well through the python program.

# -*- codeing = utf-8 -*-
# @Time : 2022/5/1 13:23
# @Author : ning
# @File : 5.1demo.py
# @software : PyCharm
 
import matplotlib.pyplot as plt
from PIL import Image
 
 
def produceImage(file_in, width, height, file_out):
    image = Image.open(file_in)
    resized_image = image.resize((width, height), Image.ANTIALIAS)
    resized_image.save(file_out)
 
 
if __name__ == '__main__':
    file_in = '9.jpg'
    width = 256 #调整的分辨率大小
    height = 256
    file_out = 'demo9.png'
    # 分辨率
    produceImage(file_in, width, height, file_out)

Python batch modification of image resolution

Use python code to specify the resolution of the image. Note: Executing this modified code will overwrite the original image with the newly generated image of the specified resolution. And this program is batch processing, which can directly specify the resolution of all pictures in the folder.

Readers only need to modify the parameters in the following two locations:

The source code is as follows:

"""
批处理文件夹train下的images和labels文件夹中的图片，进行重新修改尺寸操作，并替换保存。
注意是**批处理**，会把train中所有的文件夹下的所有图片都修改分辨率。
敲黑板，划重点！！！会直接把 原分辨率 的图片替换为 指定分辨率的图片！！！
文件夹结构：
    PATH：'/home/stu/zy/MySwin-Unet/data/train'
    childPATH：PATH下的'/labels'
    childPATH：PATH下的'images'


"""

import cv2
import os
import sys


# PATH = r'/root/autodl-tmp/MySwin-Unet/data/' # 这个路径只需写到train和val文件夹即可。文件夹下的图片程序会自动帮你打开
PATH = r'/home/stu/zy/MySwin-Unet/data/train'
# 我这里是相对路径,亲测中文路径也可以

def resizeImage(file, NoResize):
    image = cv2.imread(file, cv2.IMREAD_COLOR)

    # 如果type(image) == 'NoneType',会报错,导致程序中断,所以这里先跳过这些图片,
    # 并记录下来,结束程序后手动修改(删除)

    if image is None:
        NoResize += [str(file)]
    else:
        resizeImg = cv2.resize(image, (512, 512)) # 这里改为自己想要的分辨率
        cv2.imwrite(file, resizeImg)
        cv2.waitKey(100)


def resizeAll(root):
    # 待修改文件夹
    fileList = os.listdir(root)
    # 输出文件夹中包含的文件
    # print("修改前："+str(fileList))
    # 得到进程当前工作目录
    currentpath = os.getcwd()
    # 将当前工作目录修改为待修改文件夹的位置
    os.chdir(root)

    NoResize = []  # 记录没被修改的图片

    for file in fileList:  # 遍历文件夹中所有文件
        file = str(file)
        resizeImage(file, NoResize)

    print("---------------------------------------------------")

    os.chdir(currentpath)  # 改回程序运行前的工作目录

    sys.stdin.flush()  # 刷新

    print('没别修改的图片: ', NoResize)


if __name__ == "__main__":
    # 子文件夹
    for childPATH in os.listdir(PATH):
        # 子文件夹路径
        childPATH = PATH + '/' + str(childPATH)
        # print(childPATH)
        resizeAll(childPATH)
    print('------修改图片大小全部完成❥(^_-)')

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