Saving metadata when rotating a image?

[evilaro]

Phil:

Congratulation for ExifTool...

Already the possibility of displaying GPS data... makes worth the
learning and using of your program.

I would like to introduce myself and ask a question -advice

I have created a free program to classify-organize digital fotos

www.evilfoto.es

And here is my question... I have read all the FAQ, this forum and all the
info you offer but still I am not sure what is the best solution.


If in my program I rotate a image, the image looses its metadata (I
alredy keep the metadata on my database, but on the file it is lost)
I would like to improve on this.

Reading all your info, I have this doubts.. sorry I do not know tooo much
on all this.

a) is there any option with Exiftool to totate ±90° degrees
without loosing the metadata, and loosing as little as possible of
the image quality? Any free program that would do it?

b) Changing the orientation data on the image, so you see rotated
    but not actually.. would it be a valid solution?. what is the most
    appropiate option to do it

c) this option from your information, sends the metadata to a .mie file

exiftool -TagsFromFile aa.jpg -all:all  aa.mie

I haven't found the opposite... from .mie to the file

This looked like, but I can not make it to work.
exiftool -o -aa.mie -all:all aa.jpg     

Would this be the correct proces to restore the data.
I mean

i)    send data to a file
ii)   rotate or modify the image (loosing the data)
iii)  put the data back.

Thanks for your help.

Emilio Vilaro [evilaro]

   

[Phil Harvey]

Hi Emilio,

a) is there any option with Exiftool to totate ±90° degrees
without loosing the metadata, and loosing as little as possible of
the image quality? Any free program that would do it?

I think jhead will rotate the image data, while preserving most meta information.

b) Changing the orientation data on the image, so you see rotated
    but not actually.. would it be a valid solution?. what is the most
    appropiate option to do it

Not all software honours the EXIF Orientation tag.  Whether or not this is a good solution for you depends on what software is likely to be used with the images after rotation.

c) this option from your information, sends the metadata to a .mie file

exiftool -TagsFromFile aa.jpg -all:all  aa.mie

I haven't found the opposite... from .mie to the file

Did you try this?:

exiftool -TagsFromFile aa.mie -all:all aa.jpg

Also, I would suggest also copying the Unsafe tags, and changing Orientation when you copy the tags back, like this:

exiftool -TagsFromFile aa.mie -all:all -unsafe -orientation=normal aa.jpg

Would this be the correct proces to restore the data.
I mean

i)    send data to a file
ii)   rotate or modify the image (loosing the data)
iii)  put the data back.

Yes, this will work.  If you can find a utility that preserves the metadata it would be better of course.

- Phil

[evilaro]

Phil:

Thanks a lot for all the answers.


>I think jhead will rotate the image data, while preserving most meta information.

If I do not solve it here, I will try it.


>Not all software honours the EXIF Orientation tag.  Whether or not this is a good solution for you depends on what software is likely to be used with the images after rotation.

In this case the ONLY one that has to Honor it, is my application

>Did you try this?:
>exiftool -TagsFromFile aa.mie -all:all aa.jpg
>Also, I would suggest also copying the Unsafe tags, and changing Orientation when you copy the tags back, like this:
>exiftool -TagsFromFile aa.mie -all:all -unsafe -orientation=normal aa.jpg

No... if I did I would not have asked... because it works perfectelly..... thanks



>i)    send data to a file
>ii)   rotate or modify the image (loosing the data)
>iii)  put the data back.

>Yes, this will work.  If you can find a utility that preserves the metadata it would be better of course.

I am thinking of placing the 2 options...

Thaks a lot.

Emilio


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