Empty HEIC-encoding result with Ubuntu 24.04

[olivervogel]

I have noticed an issue when I try to encode a HEIC format with Imagick::getImagesBlob(). The result is an empty string instead of the expected image data. Strangely enough, I could only observe this in a certain Ubuntu version (24.04).

See the following code example:

 $background = new ImagickPixel('rgba(255, 255, 255, 0)'); 
 $imagick = new Imagick(); 
 $imagick->newImage(100, 100, $background, 'png'); 
 $imagick->setType(Imagick::IMGTYPE_UNDEFINED); 
 $imagick->setImageType(Imagick::IMGTYPE_UNDEFINED); 
 $imagick->setColorspace(Imagick::COLORSPACE_SRGB); 
 $imagick->setImageResolution(96, 96); 
 $imagick->setImageBackgroundColor($background); 
  
 // encode 
 $imagick->setFormat('HEIC'); 
 $imagick->setImageFormat('HEIC'); 
 $imagick->setCompressionQuality(75); 
 $imagick->setImageCompressionQuality(75); 
 $encoded = $imagick->getImagesBlob(); // results in empty string

Ubuntu 24.04
PHP 8.1 - 8.4
ImageMagick 6.9.12-98 Q16 x86_64 18038 https://legacy.imagemagick.org/

References
https://github.com/Intervention/image/pull/1402/checks