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File size smaller after lossless rotation - normal?

Posted: Mon Dec 31, 2018 2:44 am
by Benrasi
Is it normal that the file size is smaller after doing a lossless rotation?

The original file has 5262 KB, after only 4308 KB.

I notice in the EXIF a different Sub-sampling, but a better one in the rotated file. From 2x1, 1x1, 1x1 --> 1x1, 1x1, 1x1

Thanks,
Ben

Re: File size smaller after lossless rotation - normal?

Posted: Mon Dec 31, 2018 7:40 am
by cday
Are you familiar with File > Format setting... > Write -- JPEG ?

It's rather hidden, but possibly the file has also been saved with a slightly lower Quality setting?

Re: File size smaller after lossless rotation - normal?

Posted: Mon Dec 31, 2018 12:43 pm
by Benrasi
I know the setting, but it should not influence the lossless - otherwise it would be the wrong name :-) - but to make sure I checked with a much lower save quality setting and it has no result on the described difference. Normal rotation and save is done with this setting, I approved.

Can anyone try to loosless rotate an image and check the file size ?

I'm running version 0.92 on Kubuntu Linux.

Re: File size smaller after lossless rotation - normal?

Posted: Wed Jan 02, 2019 11:13 am
by xnview
the data is not changed, only compression...