Requirements
Installation requirements on non-Windows platforms
ImageMagick >= 6.2.4 is required. The amount of
file formats supported by Imagick depends entirely upon the amount
of formats supported by your ImageMagick installation. For example,
Imagemagick requires ghostscript to conduct PDF operations.
Alex Ivaylov ¶7 years ago
Unfortunately the Windows binaries downloaded from the Imagemagick website did not work with PHP 7. It seems that they used Visual C++ 2013 to compile imagemagick while PHP used Visual C++ 2015. There is another build of imagemagick which worked with PHP 7 here: http://windows.php.net/downloads/PECL/deps/