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Author Topic: How change exif data of my JPG picture?  (Read 9306 times)

seba22

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How change exif data of my JPG picture?
« on: December 13, 2010, 01:10:50 pm »
Welcome,
I have question i have picture jpg.

That picture contain metadata called exif.

Any idea how can i edit exif tags under lazarus ?

I just want repleace specificated tag for example author tag "Picasa 3.0" for mine "edited by my application xxx".

Right now im doing this using external application called exiftool but i want run this on windows and linux. So i cant use standalone application for that. I tried simple  repleace phrase "Picasa 3.0" for - "mystring mystring mystring" but it fail.

I succesfully change few letters inside exif, but overal count must be this same.

Any idea ? :>
Regards
 

Blaazen

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Re: How change exif data of my JPG picture?
« Reply #1 on: December 13, 2010, 06:01:16 pm »
There must be something like:

1) length of string (usually 2 bytes (Hi byte, Low byte)
2) text itself.

So if you need other count of letters you must change the bytes before text.

I recommend you to download some manual (specifications) of JPEG files. I have one (but old, from 1999) and here is written something about tag "COM", which is comment in jpeg file.
Lazarus 2.1.0 r64074 FPC 3.3.1 r40507 x86_64-linux-qt Chakra, Qt 4.8.7/5.13.2, Plasma 5.17.3
Lazarus 1.8.2 r57369 FPC 3.0.4 i386-win32-win32/win64 Wine 3.21

Try Eye-Candy Controls: https://sourceforge.net/projects/eccontrols/files/

DirkS

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Re: How change exif data of my JPG picture?
« Reply #2 on: December 14, 2010, 02:48:13 am »
You can find the current spec (Exif 2.3) here: http://www.cipa.jp/english/hyoujunka/kikaku/pdf/DC-008-2010_E.pdf and older specs on this page: http://www.exif.org/specifications.html.

TBH: it's far easier to use a (free) tool such as ExifTool / ExifToolGUI than to mess with this yourself...

Gr.
Dirk.

boardhead

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Re: How change exif data of my JPG picture?
« Reply #3 on: December 14, 2010, 02:51:52 pm »
Right now im doing this using external application called exiftool but i want run this on windows and linux.

... but exiftool does work on Windows and Linux (and Mac too).

The command line would be:

exiftool -software="edited by my application xxx" FILE

- Phil

seba22

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Re: How change exif data of my JPG picture?
« Reply #4 on: December 18, 2010, 09:59:23 pm »
Thank you ;)

It's working.

It's nice to see that exiftool is also compiled to Windows ;)

I think this topic is closed ;)

 

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