I have Windows 7 64 bits, PHP 5.4.3 installed through WAMP 2.2 and imagick (ImageMagick-6.8.3-9-Q16-x64-dll.exe). I tried to use the php\'s dll of imagick from
ImageMagick-6.8.3-9-Q16-x64-dll.exe
For a 64bit WAMP (PHP 5.4.x, PHP 5.4.12 thread safe in my case) a working combination is the following:
ImageMagick-6.8.7-8-Q16-x64-dll.exe or possibly latest Q16/x64/DLL from here: Link
and php_imagick-svn20120508-5.4-VC9-x64 from here: http://www.mediafire.com/php-win64-extensions