ImageMagick 无权将 PDF 转换为图像

Question

I have a program, in which I need to convert a PDF to an image using Image Magick. I do that using the subprocess package:

        cmd = 'magick convert -density 300 '+pdfFile+'['+str(rangeTuple[0])+'-'+str(rangeTuple[1])+'] -depth 8 '+'temp.tiff' #WINDOWS
        if(os.path.isfile('temp.tiff')):
            os.remove('temp.tiff')
        subprocess.call(cmd,shell=True)
        im = Image.open('temp.tiff')

The error I got is:

convert-im6.q16: not authorized `temp2.pdf' @ error/constitute.c/ReadImage/412.
convert-im6.q16: no images defined `temp.tiff' @ error/convert.c/ConvertImageCommand/3258.
Traceback (most recent call last):
  File "UKExtraction2.py", line 855, in <module>
    doItAllUpper("A0","UK5.csv","temp",59,70,"box",2,1000,firstPageCoordsUK,boxCoordUK,voterBoxCoordUK,internalBoxNumberCoordUK,externalBoxNumberCoordUK,addListInfoUK)
  File "UKExtraction2.py", line 776, in doItAllUpper
    doItAll(tempPDFName,outputCSV,2,pdfs,formatType,n_blocks,writeBlockSize,firstPageCoords,boxCoord,voterBoxCoord,internalBoxNumberCoord,externalBoxNumberCoord,addListInfo,pdfName)
  File "UKExtraction2.py", line 617, in doItAll
    mainProcess(pdfName,(0,noOfPages-1),formatType,n_blocks,outputCSV,writeBlockSize,firstPageCoords,boxCoord,voterBoxCoord,internalBoxNumberCoord,externalBoxNumberCoord,addListInfo,bigPDFName,basePages)
  File "UKExtraction2.py", line 542, in mainProcess
    im = Image.open('temp.tiff')
  File "/home/rohit/.local/lib/python3.6/site-packages/PIL/Image.py", line 2609, in open
    fp = builtins.open(filename, "rb")
FileNotFoundError: [Errno 2] No such file or directory: 'temp.tiff'

The most important of which is:

convert-im6.q16: not authorized `temp2.pdf' @ error/constitute.c/ReadImage/412.

I think this is because ImageMagick isn't authorized to access the PDF. What should be done now? I'm on a Linux server. Any help is appreciated.

Answer 1

emcconville is correct. More specifically edit the Imagemagick policy.xml file to uncomment this line:

  <!-- <policy domain="module" rights="none" pattern="{PS,PDF,XPS}" /> -->

And change it from rights="none" to rights="read|write"

  <policy domain="module" rights="read|write" pattern="{PS,PDF,XPS}" />

This was a recent addition to the policy.xml file, I believe, due to a security flaw found in the Ghostscript delegate. I think that flaw has now been fixed in the current version of Ghostscript, which is 9.25.

NOTE: On some systems the policy line will have domain="coder" rather than domain="module"

Answer 2

Quick and easy solution:

sudo mv /etc/ImageMagick-6/policy.xml /etc/ImageMagick-6/policy.xml.off

When done, you can restore the original with

sudo mv /etc/ImageMagick-6/policy.xml.off /etc/ImageMagick-6/policy.xml

Answer 3

I am using Dockerfile to update an image, and suddenly I got the policy.xml file in my way. although the version of Ubuntu (xenial) was the same and ImageMagick as well.

I ended up removing the single line causing my problem.

RUN sed -i 's/^.*policy.*coder.*none.*PDF.*//' /etc/ImageMagick-6/policy.xml

hope this helps someone

Answer 4

Use the below command to delete the policy file to fix it, If required you can also take backup of this policy file.

rm /etc/<ImageMagick_PATH>/policy.xml

for me it was ImageMagick6 and the command was :

sudo rm /etc/ImageMagick-6/policy.xml