PHP call to readImage Exception ReadPDFImage/664 Failed

[harold]

My goal is to extract about 30 JPG or PNG images from a PDF using PHP. I'm using ImageMagick 6.9.4 from PHP 7.1.8 in a shared hosting account using this code to extract one specific image:

$imagick = new Imagick();
$imagick->readImage(bound.pdf[0]);
$imagick->setImageFormat("jpeg");
$imagick->writeImage("image1.jpg");

It works perfect for the first 10 or 15 images, but gives an exception "ReadPDFImage/664 Failed" during the readImage command if I try to read bound.pdf[18] for example. I have tried several source PDFs having from 20 to 30 images each. It always works fine for the first 10 images, but starting at index X and thereafter it always gets an exception.

I tried the same test on another hosting account with PHP 7.2.9 and ImageMagick 6.7.2-7 with similar results. It always gives an exception in the readImage command when index is around 15 or higher depending on the source PDF.

Any suggestions?

[snibgo]

My goal is to extract about 30 JPG or PNG images from a PDF using PHP.

IM doesn't do that. IM will rasterize each page, no matter how many images each page has. I suspect you are trying to extract more pages than are in the document. Extracting embedded images from a PDF is a different task, which "pdfimages" does fairly well.

[harold]

Perhaps my goal description was unclear. I have a 20 page PDF file and I want to extract out 20 individual JPG files (one for each page). Each page is essentially a big image. The code above works for the first X pages, then fails with an exception. I'm trying to extract pages 0 to 19.

[snibgo]

I don't use PHP or IMagick so can't advise, but are you freeing memory correctly?

[harold]

Just these two line of code alone will cause the exception so there is never a chance to free any memory. I tried changing the memory_limit assigned to PHP, but that doesn't seem to have an affect. It seems that when you are reading a page that is far enough into the PDF file, it gets the exception.

$imagick = new Imagick();
$imagick->readImage(bound.pdf[15]);

[fmw42]

Are you sure that pdf file has 16 or more pages? The first page is [0] and you are requesting page [15] which would be the 16 page.

The Imagemagick developers have nothing to do with Imagick. Does it work with a simple convert command line?

Code: Select all

convert bound.pdf[15] result.jpg

If it does, then you will need to report the issue to the Imagick developers. See the Imagick forum.

[Bonzo]

You could try working with the first 10 pages and then the second 10 and see what happens " Each page is essentially a big image. " could be the problem as fmw42 suggested.

If it still fails try reading 5 pages at a time which will hopefully isolate the problem.

[harold]

I have tested multiple PDF files each with over 20 pages. They all fail on the readImage[X] command. Bear in mind this is running in PHP from a shared hosting account so I do not have a Command line environment to run a convert command.

To clarify, the entire script consists of only two lines. It is not running a loop and finally getting the exception on the 16th page.

$imagick = new Imagick();
$imagick->readImage(bound.pdf[15]);

My "guess" and results of testing thus far seems to indicate that the implementation of the readImage[X] command exceeds some kind of memory limitation or calculation limitation starting at page X so the exception will occur at every index of X or above. The value of X depends on the specific PDF but appears consist for a specific PDF when running this tiny PHP script from different hosting environments.

[fmw42]

It could be a limitation within PHP or Imagick and not ImageMagick.

Do you have access to PHP exec(), so that you could run the command line and see if that fails?