{"action":"created","issue":{"url":"https://api.github.com/repos/openmicroscopy/bioformats/issues/1744","labels_url":"https://api.github.com/repos/openmicroscopy/bioformats/issues/1744/labels{/name}","comments_url":"https://api.github.com/repos/openmicroscopy/bioformats/issues/1744/comments","events_url":"https://api.github.com/repos/openmicroscopy/bioformats/issues/1744/events","html_url":"https://github.com/openmicroscopy/bioformats/pull/1744","id":68964786,"number":1744,"title":"TIFF writer: automatically switch to BigTIFF when possible","user":{"login":"melissalinkert","id":109998,"avatar_url":"https://avatars.githubusercontent.com/u/109998?v=3","gravatar_id":"","url":"https://api.github.com/users/melissalinkert","html_url":"https://github.com/melissalinkert","followers_url":"https://api.github.com/users/melissalinkert/followers","following_url":"https://api.github.com/users/melissalinkert/following{/other_user}","gists_url":"https://api.github.com/users/melissalinkert/gists{/gist_id}","starred_url":"https://api.github.com/users/melissalinkert/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/melissalinkert/subscriptions","organizations_url":"https://api.github.com/users/melissalinkert/orgs","repos_url":"https://api.github.com/users/melissalinkert/repos","events_url":"https://api.github.com/users/melissalinkert/events{/privacy}","received_events_url":"https://api.github.com/users/melissalinkert/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/openmicroscopy/bioformats/labels/develop","name":"develop","color":"02e10c"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":2,"created_at":"2015-04-16T16:50:24Z","updated_at":"2015-04-17T16:57:07Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/openmicroscopy/bioformats/pulls/1744","html_url":"https://github.com/openmicroscopy/bioformats/pull/1744","diff_url":"https://github.com/openmicroscopy/bioformats/pull/1744.diff","patch_url":"https://github.com/openmicroscopy/bioformats/pull/1744.patch"},"body":"If a BigTIFF extension is used, or we know that more than 4GB of data\r\nwill be written, then BigTIFF is used automatically.  This does not\r\nattempt to switch to BigTIFF when compression is used and a BigTIFF\r\nextension is not present, as we can't easily predict the actual size\r\nof the output file in that case.\r\n\r\nFixes https://trac.openmicroscopy.org/ome/ticket/6589.\r\n\r\nTo test, take a file with 4GB or more of pixel data, e.g. ```large-file&sizeX=2048&sizeY=2048&sizeZ=1200.fake```  Run bfconvert with an output file name that has ```.btf```, ```.tf8```, or ```.tf2``` as the extension and no other arguments; the output file should be in the BigTIFF format, and there should be a ```Switching to BigTIFF``` message printed.  The same test with an output file name that ends in ```.tif``` or ```.tiff``` should print a slightly different ```Switching to BigTIFF``` message and also result in a BigTIFF output file."},"comment":{"url":"https://api.github.com/repos/openmicroscopy/bioformats/issues/comments/94026893","html_url":"https://github.com/openmicroscopy/bioformats/pull/1744#issuecomment-94026893","issue_url":"https://api.github.com/repos/openmicroscopy/bioformats/issues/1744","id":94026893,"user":{"login":"melissalinkert","id":109998,"avatar_url":"https://avatars.githubusercontent.com/u/109998?v=3","gravatar_id":"","url":"https://api.github.com/users/melissalinkert","html_url":"https://github.com/melissalinkert","followers_url":"https://api.github.com/users/melissalinkert/followers","following_url":"https://api.github.com/users/melissalinkert/following{/other_user}","gists_url":"https://api.github.com/users/melissalinkert/gists{/gist_id}","starred_url":"https://api.github.com/users/melissalinkert/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/melissalinkert/subscriptions","organizations_url":"https://api.github.com/users/melissalinkert/orgs","repos_url":"https://api.github.com/users/melissalinkert/repos","events_url":"https://api.github.com/users/melissalinkert/events{/privacy}","received_events_url":"https://api.github.com/users/melissalinkert/received_events","type":"User","site_admin":false},"created_at":"2015-04-17T16:57:07Z","updated_at":"2015-04-17T16:57:07Z","body":"My worry with doing the same thing when compression is enabled is that depending on the data and compression type, > 4GB of raw pixels could easily become < 1GB on disk (e.g. with JPEG-2000 compression), in which case switching to BigTIFF isn't strictly necessary.  It doesn't really matter from the perspective of reading the output file with Bio-Formats/OMERO, but it could easily be an issue if the output file is to be read with software that doesn't yet support BigTIFF."}}