PDF: An image could not be created from the given input

Question

I am using Spatie\PdfToImage in my Symfony application to change PDFs into images. Here is the function I am using:

public function savePdfPreviewImage($fullFilePath, $thumbnailPath)
{
    $pdf = new Pdf($fullFilePath);
    $pdf->saveImage($thumbnailPath); 

    return $this;
}

When given a path to a PDF, the library returns this message:

An image could not be created from the given input

How can I go about finding a solution to this?

So far I have tried verifying with an ls that the file exists in the place where the app thinks it is. I have also tried opening the file -- which has a .pdf file extension -- in a PDF reader to verify that it is not corrupt. Neither of those two actions yielded any clues.

=====

Edit 1: I traced this message back to the Imagine.php file, where I removed an error-suppression line. That gave me this slightly less opaque message:

Warning: imagecreatefromstring(): Data is not in a recognized format

====

Edit 2: I have also verified that ghostscript is installed. The gs command is available from my server environment. I have also verified that the path provided for $thumbnailPath is a valid path/filename ending in .jpg.

Answer 1

I figured out what the problem was.

The conversion to PDF was actually behaving just fine. What was misbehaving was a later call within the application to the Imagine.php library, unsuccessfully resizing the image that my code successfully created. Here is the code that allowed me to see this:

public function savePdfPreviewImage($fullFilePath, $thumbnailPath)
{

      //$pdf = new Pdf($fullFilePath);
      //$pdf->saveImage($thumbnailPath);    //This gives us "An image could not be created from the given input" and "Data is not in a recognized format"
                                            //Let's try it with a manual call to GhostScript instead ...

    exec(
        'gs -o ' .                //This creates the image successfully, but the error still shows up.
        $thumbnailPath .                    //That means the error isn't coming from here, since we're no longer calling any external PHP libraries.
        ' -sDEVICE=jpeg ' .
        $fullFilePath
    );

    return $this;
}

Answer 2

You do not need a lib for this, imagick alone will do fine.

$pdf = new \Imagick();
$pdf->setColorspace(\Imagick::COLORSPACE_SRGB);
$pdf->readImage($srcPath);
$pdf->setIteratorIndex($pageNo);
$pdf->writeImage($outPath);

(Imagick will recognize the file extension from $outPath)