python - ImageMagick & PyPDF2 Crashing Python When used Together

Question

I have a PDF file consisting of around 20-25 pages. The aim of this tool is to split the PDF file into pages (using PyPdf2), save every PDF page in a directory (using PyPdf2), convert the PDF pages into images (using ImageMagick) and then perform some OCR on them using tesseract (using PIL and PyOCR) to extract data. The tool will eventually be a GUI through tkinter so the users can perform the same operation many times by clicking on a button. Throughout my heavy testing, I have noticed that if the whole process is repeated around 6-7 times, the tool/python script crashes by showing not responding on Windows. I have performed some debugging, but unfortunately there is no error thrown. The memory and CPU are good so no issues there as well. I was able to narrow down the problem by observing that, before reaching to the tesseract part, PyPDF2 and ImageMagick are failing when they are run together. I was able to replicate the problem by simplifying it to the following Python code:

from wand.image import Image as Img
from PIL import Image as PIL
import pyocr
import pyocr.builders
import io, sys, os 
from PyPDF2 import PdfFileWriter, PdfFileReader


def splitPDF (pdfPath):
    #Read the PDF file that needs to be parsed.
    pdfNumPages =0
    with open(pdfPath, "rb") as pdfFile:
        inputpdf = PdfFileReader(pdfFile)

        #Iterate on every page of the PDF.
        for i in range(inputpdf.numPages):
            #Create the PDF Writer Object
            output = PdfFileWriter()
            output.addPage(inputpdf.getPage(i))
            with open("tempPdf%s.pdf" %i, "wb") as outputStream:
                output.write(outputStream)

        #Get the number of pages that have been split.
        pdfNumPages = inputpdf.numPages

    return pdfNumPages

pdfPath = "Test.pdf"
for i in range(1,20):
    print ("Run %s\n--------" %i)
    #Split the PDF into Pages & Get PDF number of pages.
    pdfNumPages = splitPDF (pdfPath)
    print(pdfNumPages)
    for i in range(pdfNumPages):
        #Convert the split pdf page to image to run tesseract on it.
        with Img(filename="tempPdf%s.pdf" %i, resolution=300) as pdfImg:
            print("Processing Page %s" %i) 

I have used the with statement to handle the opening and closing of files correctly, so there should be no memory leaks there. I have tried running the splitting part separately and the image conversion part separately, and they work fine when ran alone. However when the codes are combined, it will fail after iterating for around 5-6 times. I have used try and exception blocks but no error is captured. Also I am using the latest version of all the libraries. Any help or guidance is appreciated.

Thank you.

标签： pythonimagemagickpython-imaging-librarytesseractpypdf2

Answer 1

For future reference, the problem was due to the 32-bit version of ImageMagick as mentioned in one of the comments (thanks to emcconville). Uninstalling Python and ImageMagick 32-bit versions and installing both 64-bit versions fixed the problem. Hope this helps.