绘制到 reportlab pdf 的图像大于 pdf 纸张大小

Question

我正在编写一个程序，它可以获取给定文件夹中的所有图片并将它们聚合成一个 pdf 文件。我遇到的问题是，当绘制图像时，它们的尺寸更大并且奇怪地向左旋转。我到处搜索，甚至在 reportlab 文档中也没有找到任何东西。

代码如下：

import os
from PIL import Image
from PyPDF2 import PdfFileWriter, PdfFileReader
from reportlab.pdfgen import canvas
from reportlab.lib.units import cm
from StringIO import StringIO


def main():
    images = image_search()
    output = PdfFileWriter()
    for image in images:
        Image_file = Image.open(image)     # need to convert the image to the specific size first.
    width, height = Image_file.size
    im_width = 1 * cm
    # Using ReportLab to insert image into PDF
    watermark_str = "watermark" + str(images.index(image)) + '.pdf'
    imgDoc = canvas.Canvas(watermark_str)

    # Draw image on Canvas and save PDF in buffer
    # define the aspect ratio first
    aspect = height / float(width)

    ## Drawing the image
    imgDoc.drawImage(image, 0,0, width = im_width, height = (im_width * aspect))    ## at (399,760) with size 160x160
    imgDoc.showPage()
    imgDoc.save()
    # Get the watermark file just created
    watermark = PdfFileReader(open(watermark_str, "rb"))

    #Get our files ready

    pdf1File = open('sample.pdf', 'rb')
    page = PdfFileReader(pdf1File).getPage(0)
    page.mergePage(watermark.getPage(0))


    #Save the result

    output.addPage(page)
    output.write(file("output.pdf","wb"))

#The function which searches the current directory for image files.
def image_search():
    found_images = []
    for doc in os.listdir(os.curdir):
        image_ext = ['.jpg', '.png', '.PNG', '.jpeg', '.JPG']
        for ext in image_ext:
            if doc.endswith(ext):
                found_images.append(doc)
    return found_images

main()

我还尝试使用 im_width 变量缩放和指定纵横比，结果相同。

Answer 1

在对您的目标有点困惑之后，我发现目标是对当前文件夹中的图像制作 PDF 概览。为此，我们实际上不需要 PyPDF2，因为 Reportlab 提供了我们为此所需的一切。

请参阅下面的代码，并以注释为指导：

def main():
    output_file_loc = "overview.pdf"
    imgDoc = canvas.Canvas(output_file_loc)
    imgDoc.setPageSize(A4) # This is actually the default page size
    document_width, document_height = A4

    images = image_search()
    for image in images:
        # Open the image file to get image dimensions
        Image_file = Image.open(image)
        image_width, image_height = Image_file.size
        image_aspect = image_height / float(image_width)

        # Determine the dimensions of the image in the overview
        print_width = document_width
        print_height = document_width * image_aspect

        # Draw the image on the current page
        # Note: As reportlab uses bottom left as (0,0) we need to determine the start position by subtracting the
        #       dimensions of the image from those of the document
        imgDoc.drawImage(image, document_width - print_width, document_height - print_height, width=print_width,
                         height=print_height)

        # Inform Reportlab that we want a new page
        imgDoc.showPage()

    # Save the document
    imgDoc.save()

绘制到 reportlab pdf 的图像大于 pdf 纸张大小

Image drawn to reportlab pdf bigger than pdf paper size

python

pdf

reportlab

pypdf2