Is F-Spot changing the picture's metadata properly?

[Silvano <silvanociru gmail com>]

The description of the Preferences option "Write metadata to file" says "Enable this option to store tags and descriptions inside supported file formats". Therefore I would expect F-Spot not to change any other metadata, except "Software" and "Modification date" (what is the usual behavior when a photo is modified by some software). But activating that option changes other metadata fields! and I don't like such an unexpected behavior.

F-Spot tries to set the field "Date/Time Original" to UTC, but did I ever decided that I wanted that? Does any other application out there does it? I mean, what's the rational behind that? IMHO it's an unexpected behavior that some users don't agree with. Could anybody convince me that this is a feature that shouldn't be patch so that I don't loose my time with it? :-)

A couple of other fields have been also changed, although I don't know/understand the reason behind them.

I found out this information by comparing the metadata of a photo in its original form and after being imported by F-Spot with the option "Write metadata to file" set. The tool "exiftool" may come to help on this task. Just execute "exiftool path/photo_name > metadata_photo_name.txt" to get the metadata of each one of the photos in a file and then compare them with "diff metadata_photo_name_before.txt metadata_photo_name_after.txt". This is what I got for a photo without tags:

> < Directory                       : /tmp
> ---
> > Directory                       : /tmp/2008/10/26
> 1361c1361
> < File Modification Date/Time     : 2008:10:26 18:57:18
> ---
> > File Modification Date/Time     : 2008:10:26 18:00:15
> 1371,1372c1371,1372
> < Software                        : Ver.1.0
> < Modify Date                     : 2008:10:26 18:57:18
> ---
> > Software                        : f-spot version 0.5.0.3
> > Modify Date                     : 2008:10:26 18:00:15
> 1379c1379
> < Date/Time Original              : 2008:10:26 18:57:18
> ---
> > Date/Time Original              : 2008:10:26 17:57:18
> 1388a1389
> > Warning                         : [minor] Possibly incorrect maker notes offsets (fix by 26?)
> 1400c1401
> < Internal Serial Number          : (S06) 2008:06:19 no. 0630
> ---
> > Internal Serial Number          : ................
> 1422c1423,1424
> < Baby Age                        : 0000:16:28 00:00:00
> ---
> > Baby Age                        : 630
> > User Comment                    : 
> 1442c1444
> < Thumbnail Offset                : 8096
> ---
> > Thumbnail Offset                : 7908

What is the meaning of that warning? Did F-Spot corrupt something in the metadata of the photo? Additionally the field "Internal Serial Number" got reset and the field "Baby Age" got substituted by the last part of the original serial number. Is that a bug?

Could anybody please confirm this output?

Hasta la vista,
    Silvano

-- 
"Yo he visto cosas que vosotros no creeríais. Atacar naves en llamas más allá de Orión. He visto rayos C brillar en la oscuridad cerca de la puerta Tannhäuser. Todos esos momentos se perderán en el tiempo... como lágrimas en la lluvia..."

"I've seen things you people wouldn't believe. Attack ships on fire off the shoulder of Orion. I watched C-beams glitter in the dark near the Tannhauser gate. All those moments will be lost in time... like tears in rain..."