在網上了一個長的圖片，結果發現沒有一個合適的工具，將長圖先批量擷取為4:3格式，儲存到指定地點，然後儲存為pdf

程式碼：

from reportlab.lib.pagesizes import portrait
from reportlab.pdfgen import canvas
import os
from PIL import Image

# 按照3:4 分割圖片，返回圖片儲存結果集
def splitimage(src, dstpath):
    img = Image.open(src)
    w, h = img.size
    height=w*4/3 #3:4比例出的高度，等比縮放，算出高度
    height_dim = w*4/3 # 記錄一個固定值，方便後期呼叫
    print(height)
    num=h/height# 分割次數
    print(num)
    index=0

    s = os.path.split(src)#分割出路徑和檔名
    if dstpath == '':
        dstpath = s[0]
    fn = s[1].split('.')
    basename = fn[0]#檔名
    postfix = fn[-1]#字尾名
    img_urls=[]

    while (index < num):
        print('Index is:', index," Height is ",height)
        box = (0, height-height_dim, w, height)
        img.crop(box).save(os.path.join(dstpath, basename + '_' + str(index) + '.' + postfix), img.format)
        img_urls.append(os.path.join(dstpath, basename + '_' + str(index) + '.' + postfix))
        height = height+height_dim
        index = index + 1
    return img_urls

# 零散，大小一致圖片，儲存為pdf
def imgtopdf(input_paths, outputpath):
    index=0
    # 取一個大小
    (maxw, maxh) = Image.open(input_paths[0]).size
    c = canvas.Canvas(outputpath, pagesize=portrait((maxw, maxh)))
    for ont_path in input_paths :
        c.drawImage(ont_path, 0, 0, maxw, maxh)
        c.showPage()
        index=index+1
    c.save()



src="D:\\xvshu\\高數\\線性代數資料\\測試.png"
dstpath="D:\\xvshu\\高數\\線性代數資料\\"
imgs = splitimage(src, dstpath)
print(imgs)

# 呼叫demo:
imgtopdf(imgs, "D:\\xvshu\\高數\\線性代數資料\\測試.pdf")
print("over")