{"action":"closed","issue":{"url":"https://api.github.com/repos/openMVG/openMVG/issues/553","repository_url":"https://api.github.com/repos/openMVG/openMVG","labels_url":"https://api.github.com/repos/openMVG/openMVG/issues/553/labels{/name}","comments_url":"https://api.github.com/repos/openMVG/openMVG/issues/553/comments","events_url":"https://api.github.com/repos/openMVG/openMVG/issues/553/events","html_url":"https://github.com/openMVG/openMVG/issues/553","id":153730854,"number":553,"title":"Best approach for underwater SfM","user":{"login":"KevinCain","id":5424003,"avatar_url":"https://avatars.githubusercontent.com/u/5424003?v=3","gravatar_id":"","url":"https://api.github.com/users/KevinCain","html_url":"https://github.com/KevinCain","followers_url":"https://api.github.com/users/KevinCain/followers","following_url":"https://api.github.com/users/KevinCain/following{/other_user}","gists_url":"https://api.github.com/users/KevinCain/gists{/gist_id}","starred_url":"https://api.github.com/users/KevinCain/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/KevinCain/subscriptions","organizations_url":"https://api.github.com/users/KevinCain/orgs","repos_url":"https://api.github.com/users/KevinCain/repos","events_url":"https://api.github.com/users/KevinCain/events{/privacy}","received_events_url":"https://api.github.com/users/KevinCain/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/openMVG/openMVG/labels/question","name":"question","color":"cc317c"}],"state":"closed","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":5,"created_at":"2016-05-09T08:55:34Z","updated_at":"2016-08-23T08:23:50Z","closed_at":"2016-08-23T08:23:50Z","body":"I gather that OpenMVG requires basic camera intrinsic parameters (focal length in mm, image sensor aspect) while the remaining basic intrinsic parameter, principal point, is deduced.\r\n\r\nWhen working with underwater photos, the air/water interfaces acts like a secondary lens, which has an effect on the intrinsics.  Should I attempt to correct for the input focal length, or will the SfM process optimize the radial distortion terms in the default camera model in order to partially account for the change in the index of refraction?\r\n\r\n@pmoulon has noted that some users have successfully obtained good results with underwater, close-range photography (e.g.:  strong parallax, no weakly supported angles), so the 'best practices' here may already be known for OpenMVG.\r\n\r\nThanks for any advice or questions on this topic!"}}
{"actor":{"display_login":"pmoulon"}}