Image File naming conventions

[+sapien]

Hi there - My apologies for the cryptic title but I didn't know what else to call it.  I also don't know if this is the right location for this topic but I'm not sure where it really fits.  If it needs to be moved to somewhere else, please let me know.

 

I am already aware of the _l ending for image files, and I believe that represents a low res version of the picture.  Today I came across a png file on the GC website with a _d ending.  Does anyone know what that means?  As far as I can tell, it just seems to mean a smaller sized picture.  Is that all though?  It appears the _d doesn't work on jpg files either.  So strange.  Could someone in the know please let me know? :-)  Thanks.  I'm just trying to understand when/where I should be using the various formats of images on the website.  Does anyone else know if there are other "_x" out there?

 

Thank you in advance.

[+2Abendsegler]

_l.jpg and _l.png are the low res version of the pictures. Without the _l these are the uploaded versions. Meta data like for example Exif data are identical in both versions.

I don't know other endings. Have you an example for the _d ending?

[+barefootjeff]

27 minutes ago, 2Abendsegler said:

_l.jpg and _l.png are the low res version of the pictures. Without the _l these are the uploaded versions. Meta data like for example Exif data are identical in both versions.

 

While the urls without the _l are the same dimensions as the original, they're no longer the uploaded files as, for the last couple of years, all uploaded images are transcoded to progressive jpeg, regardless of the file type, and all metadata is stripped.

[+2Abendsegler]

1 hour ago, barefootjeff said:

While the urls without the _l are the same dimensions as the original, they're no longer the uploaded files as, for the last couple of years, all uploaded images are transcoded to progressive jpeg, regardless of the file type, and all metadata is stripped.

 

See for example first picture in GC8YRH6, hidden 23.08.2020. In both versions _l.jpg and .jpg are for example Exif data.

 

[Edit]

The metadata do not seem to be stripped, but is set to initial.

 

Edited April 11, 2021 by 2Abendsegler

[+barefootjeff]

30 minutes ago, 2Abendsegler said:

 

See for example first picture in GC8YRH6, hidden 23.08.2020. In both versions _l.jpg and .jpg are for example Exif data.

 

[Edit]

The metadata do not seem to be stripped, but is set to initial.

 

 

Curious, as I just uploaded an image from one of my puzzles which contains Author and Copyright EXIF fields. On both the uploaded version that appeared on the cache page (https://s3.amazonaws.com/gs-geo-images/6d8bc043-f4d5-43be-a358-81e57c527024_l.jpg) and the one without the _l, that EXIF data has been stripped. The original file of that image is on my own web server at https://www.barefoottimes.net/GC7J902/Plaque.jpg .

Edited April 11, 2021 by barefootjeff

[+sapien]

3 hours ago, 2Abendsegler said:

_l.jpg and _l.png are the low res version of the pictures. Without the _l these are the uploaded versions. Meta data like for example Exif data are identical in both versions.

I don't know other endings. Have you an example for the _d ending?

Thanks for the great discussion so far.

 

I've been talking to another cacher about this and they discovered another suffix too.  _t appears to be used for the thumbnail version of a picture.

 

Here's an example of a png file that "supports" _l, _d, and _t.  You can add them "randomly" which leads me to think it's the same image file no matter what but has something more to do with how the picture is processed/evaluated but what do I know?  I'm no web or graphics expert. :-b

<<https://s3.amazonaws.com/gs-geo-images/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png>>

 

 

 

[+2Abendsegler]

Ok, that's the Mars Perseverance Rover.
The pictures can also be found in the trackable: https://coord.info/TB5EFXK

 

The different versions can also be called up as follows. Here it becomes clear what they mean, even if 'large' is not really large.

https://img.geocaching.com/track/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png
https://img.geocaching.com/track/thumb/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png
https://img.geocaching.com/track/display/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png
https://img.geocaching.com/track/large/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png

[Keystone]

I do not see a website bug or feature suggestion, so I moved this thread out of that forum section.

 

What I *do* see is people helping each other, which is perfect for the "How do I...?" forum.

[+sapien]

23 hours ago, 2Abendsegler said:

Ok, that's the Mars Perseverance Rover.
The pictures can also be found in the trackable: https://coord.info/TB5EFXK

 

The different versions can also be called up as follows. Here it becomes clear what they mean, even if 'large' is not really large.

https://img.geocaching.com/track/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png
https://img.geocaching.com/track/thumb/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png
https://img.geocaching.com/track/display/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png
https://img.geocaching.com/track/large/ae3c7301-33ae-4c46-a31d-c2a8611b36d2.png

 

Heheh Yeah, I was trying to find a picture that was more "in the public domain" vs one that might cause privacy issues so I figured the Mars Rover pic was the best option. :-) 

 

Thank you for tracking down this information.  It certainly sheds some more light on this.  But now I'd like to know what the use cases are for all these different versions of the file (other than the thumbnail).  ie. When I'm linking to a picture on my cache page, which "format" should I use, especially when large/_l seems to do inconsistent things to different images?  And why doesn't display/_d work for jpg files then?  Still very weird.  At least _d has been somewhat explained now so thank you. :-)  And it appears _l doesn't mean low res any more either.  I just wish this information was documented somewhere too.  I'll keep doing some digging to see what else I can figure out.

 

The truth is out there... ;-)

 

 

[+thebruce0]

They may be remnants of old UI coding? But I can think of a few contexts, which I believe are all currently active in various places:

Thumbnail (tiny preview)

Small hover/popup (shrunk for quick viewing/gallery swiping)

Large (for an expanded/detailed view on request, shrunk if original is too large)

Original (for the raw uploaded file)

 

If the site is transcoding all images then all versions should be available for each type.

 

Edited April 13, 2021 by thebruce0