X-Git-Url: https://git.gag.com/?p=web%2Fgag.com;a=blobdiff_plain;f=bdale%2Fblog%2Fposts%2FDigital_Photo_Creation_Dates.mdwn;h=beaaf0679efd9349ebc00e5421df332c49eabe04;hp=dba0151a2faaeb51326e5c055a0faba91fe4fc61;hb=225b518a01a4f2e9fa2162f184457c71e2332058;hpb=adc437a64a169b9cbaf3b2a985edee359db7c9e1 diff --git a/bdale/blog/posts/Digital_Photo_Creation_Dates.mdwn b/bdale/blog/posts/Digital_Photo_Creation_Dates.mdwn index dba0151..beaaf06 100644 --- a/bdale/blog/posts/Digital_Photo_Creation_Dates.mdwn +++ b/bdale/blog/posts/Digital_Photo_Creation_Dates.mdwn @@ -5,7 +5,7 @@ I learned something new yesterday, that probably shouldn't have shocked me as much as it did. For legacy reasons, the "creation time" in the [Exif](https://en.wikipedia.org/wiki/Exif) metadata attached to digital camera pictures is not expressed in absolute time, but rather in some -arbitrary express of "local" time! This caused me to spend a long evening +arbitrary expression of "local" time! This caused me to spend a long evening learning how to twiddle Exif data, and then how to convince [Piwigo](https://piwigo.org/) to use the updated metadata. In case I or someone else need to do this in the future, it seems worth taking the time @@ -69,7 +69,7 @@ important, she needs to make sure her camera's time is correctly set, taking advantage of the function that allows here to set the local time from the GPS time. But of course, that only helps future photos... -# The problem +# How I fixed the problem So the problem in front of me was several thousand images taken with the camera's clock "off" by 15 hours and 5 minutes. We figured that out by a @@ -83,6 +83,12 @@ plus 4 time zones from home to where the photos were taken. And the remaining was originally set by hand, and drift of the camera's clock in the many months since then. +I thought briefly about hacking Piwigo to use the GPS time stamps, but quickly +realized that wouldn't actually solve the problem, since they're in UTC and +the pictures from our phone cameras were all using local time. There's +probably a solution lurking there somewhere, but just fixing up the times in +the photo files that were wrong seemed like an easier path forward. + A Google search or two later, and I found [jhead](https://www.sentex.ca/~mwandel/jhead/), which fortunately was already packaged for Debian. It makes changing Exif @@ -127,7 +133,7 @@ paths quickly followed: done -At this point, all the files on disk wer updated, as a little quick checking +At this point, all the files on disk were updated, as a little quick checking with exif and exiv2 at the command line confirmed. But my second problem was figuring out how to get Piwigo to notice and incorporate the changes. That turned out to be easier than I thought! Using the admin interface to go into @@ -137,6 +143,5 @@ date range (which I expressed as taken:2019-12-14..2021), then selected all photos in the resulting set, and performed action "synchronize metadata". All the selected image files were rescanned, the database got updated... -Voila! - +Voila! Happy wife!