imagemagick installed local but composer update doesn't run. OSX
I just finished installing imagemagick through brew but composer update still says it is not installed. What is the problem?
Do I need to have MAMP or XAMPP opened and running when I run composer update or it doesn't matter?
To use Imagick class in PHP you need to install both Imagemagick console tool and library and ext-imagick — php extension: PECL imagick
You just need to install PHP extension (in addition to Imagemagick you have installed already). In general yon need to run pecl install imagick. Please read PHP manual for details
In case of using MAMP if you haven't setup it's directory into $PATH you need to enter full path to MAMP's pecl. For details refer this artile Installing PHP PEAR and PECL extensions on MAMP for Mac OS X
No, you don't need MAMP to be running. On the contrary you need to restart httpd after any php.ini changes.