Please support writing exif back to image files too

[jim-meyer]

Description

This package looks like a great step up from piexifjs in many ways. Better API, supports more image formats (awesome!). But unlike piexifjs it does not support writing the Exif metadata back to an image.
The use case I have goes like this:

1. Read in the Exif from an image file
2. Change the Exif in some way. In my specific case I need to randomize the GPS coordinates so they don't reveal a precise location the image was taken. I still need the GPS location to exist to provide some sense of where the image was taken though ("somewhere within 100 miles of <<>>").
3. Save the modified Exif back to the file

(The fact this package is called ExifReader, with emphasis on "reader", did not escape my attention. I didn't let that stop me from making this request. ;-) )

Additional details

This is a feature request not a bug. Hence I'm providing no more details than what is above.

[mattiasw]

Hi!

I've been thinking it's a lot of work and code to also having the functionality to write metadata. I'm especially thinking about having to move data blocks and their pointers around in the file. But now I'm thinking there could be a middle ground where it's possible to write the fixed-sized tags (e.g. GPS values) without that much hassle, provided the tag is already present. I'm saying that without yet having looked into it at all though. 😅 Would that setup work for your use case? Are the GPS tags always present when you want to do this? It could also be that this would be the wrong path to walk down and that full support should be the goal.

Anyway, I will have a look. Can't say exactly when though. Not sure it will matter but do you use it client side or server side?

[jim-meyer]

Interesting idea @mattiasw . For my use case I only randomize GPS information that already exists in the file. If no GPS values exist, I don't need to change any Exif metadata. So your idea of supporting changing just fixed-size values should help my use case.

[digitaldutch]

Same here. For my user case I need to create the smallest image file size possible which means that I want to keep just a few exif fields.

[HarelM]

I'm also looking for piexif alternative to write images.
My use case is that I want to resize the image on the client side before uploading it, but I want to keep the location of the image with it...
My current solution is to use this package to read and use piexif-ts to write, which is not ideal from bundle size perspective...
I don't need to write to all formats, just JEPG...

[mattiasw]

It sounds like this new functionality should be made correctly instead of my earlier plan to just be able to update old fixed-sized tags. I'm still interested though, at least for JPEG and other "simple" file formats. To set expectations, this might take a while.

[chladog]

I'm also looking for piexif alternative to write images. My use case is that I want to resize the image on the client side before uploading it, but I want to keep the location of the image with it... My current solution is to use this package to read and use piexif-ts to write, which is not ideal from bundle size perspective... I don't need to write to all formats, just JEPG...

We are also in need of EXIF migration in a in-browser format conversion while keeping EXIF is high priority.
@HarelM please, any chance you could share a snippet of your solution of combining exifreader with piexif-ts to extract EXIF from any format and writing it to target JPEG? That would be greatly appreciated

[HarelM]

The code can be found here:
https://github.com/IsraelHikingMap/Site/blob/e2a4a20efbcc339866d860423c845b1d03afe356/IsraelHiking.Web/src/application/services/image-resize.service.ts#L18

[boustanihani]

This is also interesting, a Web-Assembly Port of the Perl script https://exiftool.org/ =>

https://github.com/uswriting/exiftool/