Removing metadata increases jpeg image size by 44%

*** Please report new bugs here! ***

Moderators: helmut, XnTriq, xnview, Dreamer

Post Reply
list_of_results
Posts: 2
Joined: Sat Mar 15, 2025 5:16 pm

Removing metadata increases jpeg image size by 44%

Post by list_of_results »

I have tested various methods - it's always the same result.
When I remove metadata via "Metadata" - "Clean Metadata" and then save the picture, the size increases by 22% up to 44%.

What I have discarded as cause so far:
- It's not the camera app I'm using
- It's not the camera either, as it occurs with older pictures as well and those where taken by a physical "only" camera
- I have also played around with selecting only certain metadata types to be removed

I also tried different programs like Pix image viewer and browser.
It's reproducible there.

So why is this happening and how can this be fixed?

My aim is to anonymize the images.
User avatar
g8dhe
Posts: 18
Joined: Mon Jul 27, 2009 10:51 am
Location: Worthing, UK
Contact:

Re: Removing metadata increases jpeg image size by 44%

Post by g8dhe »

Probably depends on what level of JPG compression you have set when saving the file, quite often the cameras will be set to a higher level of compression than what the program saves at, hence the overall image size increases despite having reduced the size of metadata.
Geoff G8DHE
Spherical Visions
User avatar
user0
XnThusiast
Posts: 2414
Joined: Sat May 09, 2015 9:37 am

Re: Removing metadata increases jpeg image size by 44%

Post by user0 »

list_of_results wrote: Sat Mar 15, 2025 5:36 pm When I remove metadata via "Metadata" - "Clean Metadata" and then save the picture, the size increases by 22% up to 44%.
So why is this happening and how can this be fixed?
use Metadata>Clean... in Browser, it removes metadata from file w/o re-encoding image data
Metadata>Clean Metadata... in Viewer removes metadata from loaded image, not from file
Last edited by user0 on Sat Mar 15, 2025 6:21 pm, edited 1 time in total.
cday
XnThusiast
Posts: 4396
Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Re: Removing metadata increases jpeg image size by 44%

Post by cday »

If the above post doesn't provide a solution consider g8dhe's suggestion:
g8dhe wrote: Sat Mar 15, 2025 5:53 pm Probably depends on what level of JPG compression you have set when saving the file, quite often the cameras will be set to a higher level of compression than what the program saves at, hence the overall image size increases despite having reduced the size of metadata.
You can easily compare two files' compression levels in the viewer using Image > Properties... .
list_of_results
Posts: 2
Joined: Sat Mar 15, 2025 5:16 pm

Re: Removing metadata increases jpeg image size by 44%

Post by list_of_results »

cday wrote: Sat Mar 15, 2025 6:15 pm If the above post doesn't provide a solution consider g8dhe's suggestion:
g8dhe wrote: Sat Mar 15, 2025 5:53 pm Probably depends on what level of JPG compression you have set when saving the file, quite often the cameras will be set to a higher level of compression than what the program saves at, hence the overall image size increases despite having reduced the size of metadata.
You can easily compare two files' compression levels in the viewer using Image > Properties... .
Thanks for all the quick replies.
I found in the big image under "Image > Properties" under the EXIF Tool tab and then EXIF this:
Compression JPEG (old-style)
It doesn't show in the original file.

Any clues?

I'm going to try the other suggestions.
@user0: I guess this won't work for batch processing?
User avatar
user0
XnThusiast
Posts: 2414
Joined: Sat May 09, 2015 9:37 am

Re: Removing metadata increases jpeg image size by 44%

Post by user0 »

list_of_results wrote: Sat Mar 15, 2025 6:50 pm @user0: I guess this won't work for batch processing?
you can remove metadata from multiple files in Browser
Post Reply