Add option to remove EXIF data from images/attachments (such as GPS data)

[nocte]

There should be an option to remove EXIF data from images. Leaving things like GPS data can be a serious privacy issue: Many people won't realize that this data is added to their photos and may expose more than they want.

There is an addon from @wmtech that does this for XF1, but has no XF2 equivalent.

[WMTech] Exif Location Data Remover

Description: Exif Data Remover is an essential tool for professional XenForo boards to protect their users. Nowadays with GPS connected smartphones used to shoot photos, most pictures include hidden meta data (called "Exif" for "Exchangeable...

xenforo.com

A cool feature of this addon is, that the EXIF data can still be accessed by admins.

 

[wmtech]

We also plan to update it for XF 2.1 if there won‘t be an XF integrated solution soon.

 

[duderuud]

@wmtech Any updates for an XF2 version?

 

[squirrly]

I'm also looking for this for 2.1.

 

[duderuud]

I am currently running this:

Image Optimizer for XF 2.0

Add-on have provide a powerful settings in ACP options. You MUST settings option before running optimize images. All files will be overwrite; you cannot revert the file. DESCRIPTION Optimizing all images which stored in XenForo to lower size...

xenforo.com

There is also an option to strip exit data.

 

[squirrly]

I am currently running this:

Image Optimizer for XF 2.0

Add-on have provide a powerful settings in ACP options. You MUST settings option before running optimize images. All files will be overwrite; you cannot revert the file. DESCRIPTION Optimizing all images which stored in XenForo to lower size...

xenforo.com

There is also an option to strip exit data.

Is that just for attachments, though? Or for Media Gallery?

 

[duderuud]

Both

 

[Xon]

My free add-on "Attachment improvements" implement an option to strip EXIF data (from jpegs);

Attachment Improvements By Xon

A collection of improvements to XF's attachment system. Byte-range support for resumable downloads Primarily designed for partial content requests for streaming videos, but will work with any file Dependant on the filesystem /internal_data...

xenforo.com

 

[trapped_soul]

My free add-on "Attachment improvements" implement an option to strip EXIF data (from jpegs);

Attachment Improvements By Xon

A collection of improvements to XF's attachment system. Byte-range support for resumable downloads Primarily designed for partial content requests for streaming videos, but will work with any file Dependant on the filesystem /internal_data...

xenforo.com

Another cracker from @Xon thank you!

 

[Kirby]

My free add-on "Attachment improvements" implement an option to strip EXIF data (from jpegs)

Attachment Improvements By Xon

A collection of improvements to XF's attachment system. Byte-range support for resumable downloads Primarily designed for partial content requests for streaming videos, but will work with any file Dependant on the filesystem /internal_data...

xenforo.com

Hmm, I might be wrong but as far as I can see you are stripping the EXIF data by re-saving the image with JPEG quality 100?

If so, i think this approach has several drawbacks:

• It doesn't work with ImageMagick
• It might decrease image quality
• It significantly increases the filesize

Especially the last one seems really serious to me - the size of my test image increased from 2.9 MB to 6.1 MB (GD) / 4.4 MB (ImageMagick); the IM-version even still had the GPS EXIF afterwards.

IMHO this needs to be done without reencoding, eg. by just stripping metadata like it is done by jpegoptim, exiftool, etc.

 

[nocte]

This one works quite well for just stripping GPS EXIF data:

GitHub - pel/pel: PHP Exif Library - library for reading and writing Exif headers in JPEG and TIFF files using PHP.

PHP Exif Library - library for reading and writing Exif headers in JPEG and TIFF files using PHP. - GitHub - pel/pel: PHP Exif Library - library for reading and writing Exif headers in JPEG and TIF...

github.com

 

[Xon]

IMHO this needs to be done without reencoding, eg. by just stripping metadata like it is done by jpegoptim, exiftool, etc.

I don't use IM because it is a buggy & insecure mess, but I didn't realise it was causing the image sizes to increase. I think just stripping the metadata would be saner, but stock php doesn't have anything which does that natively so hopefully a library (like Nocte linked) works well instead