Filsize reduced by 20 Kb after Orientation change

[alpha-nbg]

Hello,

if i try to change the Orientation of a jpg it works correct.

Code Select Expand


exiftool -Orientation -S P4070201.JPG
Orientation: Horizontal (normal)

exiftool -Orientation=8 -n P4070201.JPG
    1 image files updated

exiftool -Orientation -S P4070201.JPG
Orientation: Rotate 270 CW


But what makes me wonder is, the filesize is reduced by 20 kb after this operation.
original: 6.442 KB
after rotation: 6.423 KB
How can that be? It should be changed only a little header information.

regards,
Armin.

[Phil Harvey]

Hi Armin,

This is FAQ number 13.

- Phil

[alpha-nbg]

Hello Phil,

Thank you very much for this information.
Now I understand it.

regards,
Armin