python实现图片切割和合并

在进行滑块验证码图像还原的过程中，需要用到图片切割成小的图像块，然后根据给定的排序对小的图像块进行重新组合。

目录

 一、将原图进行切割

二、切割之后的图片

三、还原之后的图片

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未切割前的图片

 一、将原图进行切割

根据分析，原图像大小尺寸为：宽：300px,高：200px

需要将原图切割为：宽：30px ，高：100px ,共20块

from PIL import Image
import numpy as np
import cv2
import os


# 切割图片
def splitimage(src, rownum, colnum, dstpath, arr):
    img = Image.open(src)
    w, h = img.size
    if rownum <= h and colnum <= w:
        print('原图基本信息:宽:{}px,高:{}px,图片格式:{}'.format(w, h, img.format))
        print('图片切割开始处理, 请稍候...')
        s = os.path.split(src)
        if dstpath == '':
            dstpath = s[0]
        fn = s[1].split('.')
        basename = fn[0]
        ext = fn[-1]
        num = 0
        rowheight = h // rownum
        colwidth = w // colnum
        for r in range(rownum):
            for c in range(colnum):
                box = (c * colwidth, r * rowheight, (c + 1) * colwidth, (r + 1) * rowheight)
                img.crop(box).save(os.path.join(dstpath, rewrite_filename(arr.pop()) + '.' + ext), ext)
                num = num + 1

        print('图片切割完成，共生成 {}张小图片'.format(num))
    else:
        print('行列切割参数不合法')


# 合并图片
def merge_picture(merge_path, num_of_cols, num_of_rows):
    filename = file_name(merge_path, ".png")
    shape = cv2.imread(filename[0], -1).shape  # 三通道的影像需把-1改成1
    cols = shape[1]
    rows = shape[0]
    channels = shape[2]
    dst = np.zeros((rows * num_of_rows, cols * num_of_cols, channels), np.uint8)
    for i in range(len(filename)):
        img = cv2.imread(filename[i])
        m, n = filename[i].split("\\")[-1].split(".")[0].split("_")
        cols_th = int(n)
        rows_th = int(m)
        roi = img[0:rows, 0:cols, :]
        dst[rows_th * rows:(rows_th + 1) * rows, cols_th * cols:(cols_th + 1) * cols, :] = roi
    cv2.imwrite(merge_path + "merge.png", dst)


# 遍历文件夹下的图片
def file_name(root_path, picturetype):
    filename = []
    for root, dirs, files in os.walk(root_path):
        for file in files:
            if os.path.splitext(file)[1] == picturetype:
                filename.append(os.path.join(root, file))
    return filename


# 重写文件名称
def rewrite_filename(num):
    num = int(num)
    if (num < 10):
        return "0_{}".format(num)
    else:
        i = num % 10
        return "1_{}".format(i)


if __name__ == '__main__':
    # 正确的文件块顺序
    arr = "18,13,9,5,3,10,2,7,19,14,6,1,12,17,11,0,8,15,4,16".split(",")
    arr.reverse()
    # 切割图片
    splitimage(r'E:\vdemo\img\code.png', 2, 10, r'E:\vdemo\img\file', arr)
    # 合并图片
    merge_picture(r'E:\vdemo\img\file', 10, 2)

二、切割之后的图片

切割之后的图片

三、还原之后的图片

还原之后的图片