Thanks for the extensive reply. Image meta data is spread across different "formats" seemingly invented by different associations at different points in time, and it's a bit of a mess to be honest.
rsteves Digikam seems to propagate this data to multiple different fields in the metadata.
I am guessing many apps do the same, because there is not one single preferred standard, although IPTC is most common.
rsteves For an image where I set Title="MyTitle" and Caption="MyCaption" and Tag=Year/1899, the ExifTool tab in Digikam shows the following:
Good to know. So from your image, Files Gallery will use IPTC ObjectName
as well as other IPTC values in your screenshot, and some that are not in your screenshot. IPTC doesn't even have proper names, so fields are extracted to Files Gallery items that I just call title
, headline
and description
etc.
XMP is another popular meta data format, but PHP does not support this without heavy external libraries. Exif is mostly used to store technical camera data written to the image when the photo is taken. It's likely it can store other values like "title", but this isn't commonly used from Exif.
rsteves I'd still find it useful to have more control over which fields get displayed. For example, for my purposes I may prefer not to show the filename, resolution, size, or date... possibly just Caption and Keywords.
This can be achieved in CSS by simply hiding the meta elements you don't want to display. It's not useful to create individual settings for every single tiny interface element in Files Gallery, as that would bloat the config incomprehensible, and it's easier to just hide elements. Let me know if you need any help with custom CSS for this.
rsteves I also prefer if I can show the XMP/TagsList field instead of the IPTC/Keywords field since Digikam stores the full tag path including parent tags in the former field (ex "Year/1899" instead of just "1899"). Maybe a config setting to override the default behaviour and manually specify the metadata to show?
Unfortunately, PHP (on your server) simply doesn't support reading XMP. Besides, it's unclear what this TagsList
is and how it's supposed to display. To me, People/Bill Smith, People/Robert Hill, People/Dan Stevens
doesn't look like a logical format, unless your app is using it internally for tags and search. This data would look better directly in a caption or even as keywords.
rsteves I also think I'd prefer a permanently visible "information sidebar" with field labels.
There is no room for a "sidebar" on mobile devices, certainly not permanently visible. A permanent sidebar would mostly be suitable for large wide screens displaying a portrait aspect image. As soon as it's landscape image, and you limit the width with a permanent sidebar, the photo will be very small unless you are viewing from a large screen. It could work nicely for some images across large screens, but it's not flexible to work with, and it doesn't emphasize the photo. Also, it would really only be useful if you have long multi-line captions. I would need to think about it!
In my opinion, your example is bloated. When it says image/jpeg
, even if you need or care about this (it's obviously an image), you don't need header MIME Type
. Image size 3181 x 3988 px
doesn't need a header Image Size
, and neither does file size 2.1 MB
. Tags list Bill Smith
doesn't need to be prepended with People
, as we can already see that is a person. Also headers Title
and Image Description
seem pointless if My title is bold, followed by the caption. Just my thoughts!