Option to send images with metadata

[mlietze]

• I have searched open and closed issues for duplicates

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Feature Description

I would like to have the possibility to send picture files just as they are.

For privacy reasons it totally makes sense to strip all EXIF data in general. File names, recording timestamp, GPS coordinates and stuff. But I would like to have an option to share raw pictures with my best friends without using nextcloud links or email or so.

Steps to Reproduce

1. Share a picture
2. Download this pictures
3. Try to figure out when or where it got captured

Actual Result:

You can often estimate if it is day or night, winter or summer by just watching the image.

Expected Result:

You have an option to just send the original timestamp and maybe all EXIF data quite with the file itself.

[brandnewx]

You should just zip the image before upload. That's all it takes.

[mlietze]

It's quite hard to open (or create) ZIP-Files on mobile devices. If I just want to share an original picture file with someone, he/she should have the option to decide on with device he/she wants to open/view it.

[mailinglists35]

whatsapp - which is always one step ahead in terms of usability - have done it cleanly this way:

• send a pic? downscale and strip metadata
• send a document? send unaltered jpg file

why does it take signal ages to eventually catch up? it's clearly not a technical issue, but a political resistance against everything that is not designed by open whisper systems. they may be good at cryptography but total disaster at usability.

[indutny-signal]

I'm sorry to hear this is causing troubles for you.

Could you talk a bit more about your use case:

• What metadata should be preserved?
• How would you suggest Signal should determine if the .jpeg attachment is an image or a document? Is there some metadata that communicates that?

Thanks for your report!

[mailinglists35]

this talk applies to all platforms, not just desktop. please discuss it with your team for ios and android as well.

What metadata should be preserved?

https://en.wikipedia.org/wiki/Metadata#Photographs

How would you suggest Signal should determine if the .jpeg attachment is an image or a document? Is there some metadata that communicates that?

you don't. instead you give the user the choice and decision.
whatsapp has a plus sign (ios) or paperclip (web) where you can choose, among others:

• photo
• document

if user chooses photo, user navigates the photo library and the app downscales it and strips all metadata
if user chooses document, user navigate the device file storage and the app sends it as a 1:1 binary file, thus preserving existing metadata and original quality

[indutny-signal]

Thanks for this information.

[brandnewx]

It's absolutely unacceptable to allow users to send images with metadata unstripped. Metadata inside image files can contain GPS location when the photos are taken, the exact phone model and possibly real names.

However, the option to send images at full resolution should be added. This means the image files must be recompressed using pixels data only so that metadata will never be accidentally reincluded (bug in code or user error) in the new images to be sent.

For advanced users that need to send original image files with metadata intact, they can do so by zipping the files first and use Signal to send the zip file. This means you do it intentionally.

[mlietze]

I'm not quite sure why you want to forbid users to do it. You don't forbid users to write where they are or where they took a photo. You can even share a location via Signal.
Why shouldn't you leave it up to the user to decide whether he wants to send the original pictures with all its data?

[adioe3]

Metadata stripping should be an opt-in configuration option. If we're advocating very strong privacy then maybe opt-out but configurable in any case. What if I want the recipient to have the EXIF data? I would expect any file shared with someone via Signal to arrive unaltered at the other end, be it a JPEG or ODT.

[ITaluone]

For privacy reasons it totally makes sense to strip all EXIF data in general. File names, recording timestamp, GPS coordinates and stuff. But I would like to have an option to share raw pictures with my best friends without using nextcloud links or email or so.

BTW... There is no advantage in stripping the recording timestamp, if behind the scences the image is called "signal-YYYY-MM-DD-HHmmss"..
(Yeah.. I know... this "timestamp" is when the image was sent, but when do you really take a picture with signal and not sending it afterwards 🤔)

I think a better way is to just create a GUID for it..

[zylstra]

Has this option been implemented? If so, where?

Edit: I ask because just above it says, "...closed this as completed on Sep 29, 2021".

[atomhamster]

This Feature would be absolutly gamechanging. Let users opt in if they want to share exif and gps. When I am on a trip with my friends, I want to share our pictures in full quality and with all exif includes. This should be a standard feature Oo

[zylstra]

For all future visitor to this thread:
Github Issues are for bugs; the Signal Community forum is for feature requests. This particular feature can be upvoted here, https://community.signalusers.org/t/add-option-to-keep-or-strip-meta-data/3005/ .

[mailinglists35]

this issue IS a bug. because it is a REGRESSION (sometime ago it was possible to send unstripped exif images, now it is not). what if I want to securely send someone an images containing important metadata? whatsapp allows for this purpose sending files, so you just pick a JPG/HEIC file from the mobile os Files app.