The Official EXIF Thread
-
I think the bigger is whichever numbskull decided that mobile devices should include PII in the EXIF by default. Author/copyright/device/etc info should all be empty BY DEFAULT.
-
@bb36e most of that isn't unique enough to be PII. The real gotcha is GPS tagging... which can be quite useful, if you know it's there.
-
@anotherusername said in The Official EXIF Thread:
If all it's doing is stripping EXIF, I agree. If it's also resizing, though (which is already a lossy operation), it might as well go the rest of the way and apply the rotation (also a lossy operation... usually▶) so the resulting image has the default orientation.
It does.
-
@anotherusername Yeah, enabling GPS location on photos by default is pure evil.
Idea: in every program (where it's reasonably easy to do so), it should be a standard feature to detect images with GPS info, and add a button on the lower right with an icon like or that actually opened a map to that location (embedded or in a new window, whatever's easier).
Not only it would be reasonably useful (hey, the information's there, so you might as well use it), it would make that "hidden" information much more visible. And map embeds are free and easy nowadays (I believe Windows, Android and iOS all offer them as a standard widget).
-
Another interesting way to leak PII is when the EXIF contains a thumbnail. Occasionally you'll run into an image that's been censored, but which contains all of the original image's EXIF data -- including its (unmodified) thumbnail. It's low res, but it's there.
Proper tools will either know that the thumbnail exists and replace it with a new thumbnail generated from the edited image, or let you opt to leave the thumbnail out entirely.
This post is not fake news... but try posting a screenshot of it, I dare ya.
-
@heterodox said in The Official EXIF Thread:
@anotherusername said in The Official EXIF Thread:
If all it's doing is stripping EXIF, I agree. If it's also resizing, though (which is already a lossy operation), it might as well go the rest of the way and apply the rotation (also a lossy operation... usually▶) so the resulting image has the default orientation.
It does.
We're not using the built-in image code. We're using nodebb-plugin-imagemagick.
So my question is, why isn't that code fixing it? The pull request is added by the Dockerfile.
-
@ben_lubar already figured out that when he cropped the image on his phone, it wasn't saved with the correct orientation flag after. So the image he uploaded was wrong to begin with, and it's his phone's fault, not the forum's.
-
@blakeyrat said in The Official EXIF Thread:
I was doxxed during the Discourse years because Discourse was coded by retarded idiot morons who never stop to think about anything, and didn't bother to remove personally-identifying meta-tags before sharing the file with the entire universe, an extremely obvious bug any decent software developer would have caught had they spent even a few seconds thinking about how their product should behave.
Wait, why is this "obviously" the software's responsibility and not the user's? These things are highly context-sensitive. A user might not care if certain personally-identifiable information is in there, or might even prefer it (for example, to help establish the identity of the original photographer) where a different user might want to keep such details private.
-
@tsaukpaetra said in The Official EXIF Thread:
And if it happens to look like a
nude persondesert landscape kinda-sorta? Auto-Ban!
-
@masonwheeler said in The Official EXIF Thread:
@tsaukpaetra said in The Official EXIF Thread:
And if it happens to look like a
nude persondesert landscape kinda-sorta? Auto-Ban!I couldn't tell the difference, so I went with the safe option.
-
@bb36e Oh, I want my phone to save these (well, GPS) when I take a picture. That can be useful much later. But that should be accessible only to the internal picture gallery.
It should be stripped automatically by the gallery API whenever another app uses it to access pictures, including the browser's upload function.
-
@blakeyrat Stop being so oppressive! It has whatever orientation it says it has!
-
So I may have skimmed past the answer to this, but is there an orientation EXIF tag that matters for how the image is displayed? Why can't the software that made the original jpeg do it in such a way that its EXIF isn't necessary to display the image correctly?
-
-
@coderpatsy said in The Official EXIF Thread:
So I may have skimmed past the answer to this
Yes, you did.
In summary, pictures are made of tiles, pictures that aren't exactly square have problems, and cameras of ye olde times couldn't math the things on the spot well enough to have orientation right on the get-go, so instead just put a flag that said "When I encoded this image the camera was flipped this-a-way".
It became popular, and so it stayed.
-
EXIF is stupid and everything should strip it by default, but rotating the jpeg to it's correct orientation before doing that.
-
@sockpuppet7 said in The Official EXIF Thread:
EXIF is stupid and everything should strip it by default, but rotating the jpeg to it's correct orientation before doing that.
Thanks for the TL;DR:
Have we built a good enough echo chamber yet?
-
@anonymous234 said in The Official EXIF Thread:
Thankfully, Windows does it. Right click-> properties
Woah! Advanced techniques here!
Seriously, many users really aren't able to cope with multiple mouse buttons. It's dumb… but the truth.
-
@anotherusername said in The Official EXIF Thread:
it's his phone's fault
To be fair, his phone is rather enlightened…
-
@dkf said in The Official EXIF Thread:
Seriously, many users really aren't able to cope with multiple mouse buttons. It's dumb… but the truth.
That link sucks, lemme find a vid...
-
-
@tsaukpaetra said in The Official EXIF Thread:
@coderpatsy said in The Official EXIF Thread:
So I may have skimmed past the answer to this
Yes, you did.
In summary, pictures are made of tiles, pictures that aren't exactly square have problems, and cameras of ye olde times couldn't math the things on the spot well enough to have orientation right on the get-go, so instead just put a flag that said "When I encoded this image the camera was flipped this-a-way".
It became popular, and so it stayed.
Plus it makes it dirt simple to rotate an image (and ridiculously fast, too). You're just changing the EXIF tag.
There's nothing really wrong with an EXIF-based orientation flag, on a conceptual level. It just wasn't supported very well at first, and that's rather unfortunate. As long as the image decoder/displayer handles it properly, the user might as well not even know it's there.
-
@anotherusername said in The Official EXIF Thread:
@hungrier said in The Official EXIF Thread:
You cropped out my signature?
What signature?
-
@anotherusername said in The Official EXIF Thread:
@hungrier said in The Official EXIF Thread:
You cropped out my signature?
It, too, was fake news.
-
@tsaukpaetra said in The Official EXIF Thread:
@anotherusername said in The Official EXIF Thread:
@hungrier said in The Official EXIF Thread:
You cropped out my signature?
What signature?
That signature.
You're on mobile. I guess that's why it doesn't work. Stupid mobile browser not displaying my PNG pixel-for-pixel, the size that
GodI intended...
-
@anotherusername said in The Official EXIF Thread:
You're on mobile.
No, I have the text zoom increased from the default. :P
-
@tsaukpaetra that's what she said. :P
-
@anotherusername said in The Official EXIF Thread:
@tsaukpaetra that's what she said. :P
If she's satisfied, who am I to complain?
-
@anotherusername said in The Official EXIF Thread:
I guess that's why it doesn't work.
It looks like a grubby smudge to me (desktop Chrome). Is that what you intended?
-
@anotherusername said in The Official EXIF Thread:
As long as the image decoder/displayer handles it properly, the user might as well not even know it's there.
And, indeed, most don’t until they try posting the image to a forum.
-
@anotherusername said in The Official EXIF Thread:
@hungrier said in The Official EXIF Thread:
You cropped out my signature?
-
@dkf said in The Official EXIF Thread:
@anotherusername said in The Official EXIF Thread:
I guess that's why it doesn't work.
It looks like a grubby smudge to me (desktop Chrome). Is that what you intended?
Sort of. It's not really about what it looks like to your eyes... go back up and try quoting my original post; that will show you what I'm talking about (because I posted the same -- basically -- blurry smudge image in the post itself for that one).
A screen shot will do the same thing you see when quoting, if the background is a solid color (the image is mostly transparent), and if the device is displaying the image at 1:1 size (pixel for pixel).
edit: or quote @sockpuppet7's post just above this one.