1nterval/grayscale — pull request #1 by jeffhertzler (2014-09-15 10:05:20+00:00)
Title: Don't cast $crop to bool

Since WordPress 3.9 you can optionally pass an array that will determine from where the crop occurs. Casting to a boolean prevents this functionality from being used with your plugin.

https://github.com/WordPress/WordPress/blob/master/wp-includes/media.php#L473