图像处理——切割图像块

import os
import math
from PIL import Image

'''
由于输入图片大小是256*256=65536
为了整张图像素点都能使用上，且数量足够多，所以定义裁剪图片大小为32，裁剪成64块（64*32*32=65536）
'''
patch_size=32  # 自定义定义裁剪图片大小，默认长宽等比例
# 一张图需要切割成多少块
img_num = 64

folder = r'./train_imgs/mri/'  # 待切割图片存储位置
path = os.listdir(folder) # 得到所有待切割图片

# 定义要存放切割结果图的目录，若没有则会自动创建
mkpath = r"./patch_imgs/patch_mri/"


def main():
    for each_bmp in path:  # 批量操作  # path[0] = '1.png'
        first_name, second_name = os.path.splitext(each_bmp) # ('1', '.png')
        each_bmp = os.path.join(folder, each_bmp) # './train_imgs/mri/1.png'
        src = each_bmp
        print(src)
        print(first_name) # 1
        # 调用函数
        mkdir(mkpath)
        if os.path.isfile(src): # True
            dstpath = mkpath
            if (dstpath == '') or os.path.exists(dstpath):
                if patch_size > 0:
                    splitimage(src, patch_size, patch_size, dstpath)
                else:
                    print('无效的图片大小')
            else:
                print('图片保存目录 %s 不存在！' % dstpath)
        else:
            print('图片文件 %s 不存在！' % src)

# 切割图片
def splitimage(src, rownum, colnum, dstpath):
    img = Image.open(src)
    w, h = img.size # 256,256
    if rownum <= h and colnum <= w: # 小于源图像大小
        print('Original image info: %sx%s, %s, %s' % (w, h, img.format, img.mode))
        print('图片切割img...')

        s = os.path.split(src)  # ('./train_imgs/mri', '1.png')
        if dstpath == '':
            dstpath = s[0]  #  './train_imgs/spect'
        fn = s[1].split('.') # ['1', 'png']
        basename = fn[0] # '1'
        ext = fn[-1] # 'png'

        number = 0
        rowheight = rownum  # 24
        colwidth = colnum  # 24
        num = int(math.sqrt(img_num))
        for r in range(num): # 0-65   8：19200    9:24300
            for c in range(num): # 0-65
                box = (c * colwidth, r * rowheight, (c + 1) * colwidth, (r + 1) * rowheight) # (0, 0, 24, 24)
                # Image.crop(left, up, right, below)   https://www.cnblogs.com/zrmw/p/11467046.html
                img.crop(box).save(mkpath+os.path.join(basename + '_' + str(number) + '.' + ext), ext)
                number = number + 1

        print('共生成 %s 张小图片。' % num)
    else:
        print('error')

# 创建文件夹
def mkdir(path):
    # 去除首位空格
    path = path.strip()
    # 去除尾部 \ 符号
    path = path.rstrip("\\")

    # 判断路径是否存在
    # 存在     True
    # 不存在   False
    isExists = os.path.exists(path)

    # 判断结果
    if not isExists:
        os.makedirs(path)
        # print(path + ' 创建成功')
        return True
    else:
        # print(path + ' 目录已存在')
        return False


if __name__ == '__main__':
    main()

部分图像块：