python常用图像处理操作总结

1.批量裁剪指定大小的数据图片集

from PIL import Image
import os.path

# 指明被遍历的文件夹
rootdir = r'F:\scientific research'

for parent, dirnames, filenames in os.walk(rootdir):  # 遍历每一张图片
    for filename in filenames:
        print('parent is :' + parent)
        print('filename is :' + filename)
        currentPath = os.path.join(parent, filename)
        print('the fulll name of the file is :' + currentPath)

        img = Image.open(currentPath)
        print(img.format, img.size, img.mode)
        # img.show()
        box1 = (856, 529, 1316, 989)  # 设置左、上、右、下的像素
        image1 = img.crop(box1)  # 图像裁剪
        image1.save(r"F:\scientific research\result10.28_1" + '\\' + filename)  # 存储裁剪得到的图像

2.获取图像灰度直方图信息

2.1 单张image

import cv2
import numpy as np
import matplotlib.pyplot as plt

# 读取彩色图像
img = cv2.imread('DSC_3681.JPG')

# 将彩色图像转换为灰度图像
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# 计算灰度直方图
hist, bins = np.histogram(gray.ravel(), 256, [0, 256])

# 输出灰度直方图信息
plt.hist(gray.ravel(), 256, [0, 256])
# 添加图例
plt.xlabel('Pixel value')
plt.ylabel('Pixel count')
plt.title('Grayscale Histogram')
plt.show()

2.2 批量获取

3.