{"action":"created","issue":{"url":"https://api.github.com/repos/jcupitt/libvips/issues/393","repository_url":"https://api.github.com/repos/jcupitt/libvips","labels_url":"https://api.github.com/repos/jcupitt/libvips/issues/393/labels{/name}","comments_url":"https://api.github.com/repos/jcupitt/libvips/issues/393/comments","events_url":"https://api.github.com/repos/jcupitt/libvips/issues/393/events","html_url":"https://github.com/jcupitt/libvips/issues/393","id":136069751,"number":393,"title":"Best vips_sharpen() settings for general photography resizing?","user":{"login":"davidb2002","id":244506,"avatar_url":"https://avatars.githubusercontent.com/u/244506?v=3","gravatar_id":"","url":"https://api.github.com/users/davidb2002","html_url":"https://github.com/davidb2002","followers_url":"https://api.github.com/users/davidb2002/followers","following_url":"https://api.github.com/users/davidb2002/following{/other_user}","gists_url":"https://api.github.com/users/davidb2002/gists{/gist_id}","starred_url":"https://api.github.com/users/davidb2002/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/davidb2002/subscriptions","organizations_url":"https://api.github.com/users/davidb2002/orgs","repos_url":"https://api.github.com/users/davidb2002/repos","events_url":"https://api.github.com/users/davidb2002/events{/privacy}","received_events_url":"https://api.github.com/users/davidb2002/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":8,"created_at":"2016-02-24T14:02:14Z","updated_at":"2016-02-25T16:23:36Z","closed_at":null,"body":"I'm currently using ImageMagick to resize and sharpen images. I'm now moving to VIPS due to performance reasons.\r\n\r\nI use imageMagick's unsharpMask (http://php.net/manual/en/imagick.unsharpmaskimage.php) feature to sharpen a photo after resizing it. I'm currently using the following settings:\r\n```\r\nRadius: 0\r\nSigma: .5\r\nAmount: .25\r\nthreshold: .008\r\n```\r\n\r\nvips_sharpen (http://www.vips.ecs.soton.ac.uk/supported/7.42/doc/html/libvips/libvips-convolution.html#vips-sharpen) has a number of additional parameters which i'm trying to replicate the same sharpening results.\r\n\r\nDoes anyone know an easy way to work out the VIPS translation of the imagemagick unsharp mask settings? There must be some sort of formula? Or what is a best 'general' sharpening settings for all round photography. It's to be used on a photography community of professional photographers. so I need a pretty good setup.\r\n\r\nThanks,\r\nDavid\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/jcupitt/libvips/issues/comments/188861844","html_url":"https://github.com/jcupitt/libvips/issues/393#issuecomment-188861844","issue_url":"https://api.github.com/repos/jcupitt/libvips/issues/393","id":188861844,"user":{"login":"KarlAustin","id":5338970,"avatar_url":"https://avatars.githubusercontent.com/u/5338970?v=3","gravatar_id":"","url":"https://api.github.com/users/KarlAustin","html_url":"https://github.com/KarlAustin","followers_url":"https://api.github.com/users/KarlAustin/followers","following_url":"https://api.github.com/users/KarlAustin/following{/other_user}","gists_url":"https://api.github.com/users/KarlAustin/gists{/gist_id}","starred_url":"https://api.github.com/users/KarlAustin/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/KarlAustin/subscriptions","organizations_url":"https://api.github.com/users/KarlAustin/orgs","repos_url":"https://api.github.com/users/KarlAustin/repos","events_url":"https://api.github.com/users/KarlAustin/events{/privacy}","received_events_url":"https://api.github.com/users/KarlAustin/received_events","type":"User","site_admin":false},"created_at":"2016-02-25T16:23:36Z","updated_at":"2016-02-25T16:23:36Z","body":"It was actually doing a shrink-on-load + shrink + affine :)\r\n\r\nTried master and yes, it's a lot quicker now using vips_resize() than it was when tested with a release."}}