Well, let me explain what I found.
First I have only worked with Raj photo.
Second, we have found that at least, the pictures where saved with Photoshop CS2 windows.
At this point, the only thing that we can say is that the photo were not directly taken from the memory card and put on the hard drive. It passed throw Photoshop.
But there is more... I found this simply by examinating the files with Notepad !
When you save a Picture under Photoshop, it gets two Id: An
InstanceId, and a
DocumentId (I will talk only about the DocumentId)
But when you are saving AGAIN your work, it also keep track of the last documentId from where it came frome. You can find those data after the
DerivedFrom tag.
So let's see the story of a photo I took with my personnal camera:
-First photo taken from the Memory card: No Meta Data except the Exif data.
-Then I save this image with Photoshop: It gets a DocumentID. But NO DerivedFrom:DocumentId
-Then I save it again with Photoshop: It gets a NEW DocumentID and it gets a DerivedFrom:DocumentId ! And of course this last number is the same that the documentId where it came from.
Here is the results of test I have done:
Original photo taken from my camera (PIC1):No Meta-Data after the EXIF data (or not visible !)
Original photo saved one time with Photoshop (PIC2)xapMM:DocumentID="uuid:AE99BC821263DD119FEAF7D6B9E8CD07"
<xapMM:DerivedFrom rdf:parseType="Resource"/>
PIC2 with colors corrections and play with Eraser Tool (PIC3):xapMM:DocumentID="uuid:2C6DE19F1363DD119FEAF7D6B9E8CD07"
<xapMM:DerivedFrom
stRef:instanceID="uuid:AF99BC821263DD119FEAF7D6B9E8CD07"
stRef:documentID="uuid:AE99BC821263DD119FEAF7D6B9E8CD07"
/>
PIC2 saved again without touching it (PIC4):xapMM:DocumentID="uuid:0A5608501463DD119FEAF7D6B9E8CD07"
<xapMM:DerivedFrom
stRef:instanceID="uuid:AF99BC821263DD119FEAF7D6B9E8CD07"
stRef:documentID="uuid:AE99BC821263DD119FEAF7D6B9E8CD07"
/>
PICT13 from Raj<xapMM:DerivedFrom rdf:parseType="Resource">
<stRef:instanceID>uuid:466E2C450D07DC119FD78ABD8FA3219B</stRef:instanceID>
<stRef:documentID>uuid:B546BEBB0507DC119FD78ABD8FA3219B</stRef:documentID>
</xapMM:DerivedFrom>
PICT14 from Raj<xapMM:DerivedFrom rdf:parseType="Resource">
<stRef:instanceID>uuid:5465D66D1307DC119FD78ABD8FA3219B</stRef:instanceID>
<stRef:documentID>uuid:F8D02F7C0D07DC119FD78ABD8FA3219B</stRef:documentID>
</xapMM:DerivedFrom>
PICT15 from Raj<xapMM:DerivedFrom rdf:parseType="Resource">
<stRef:instanceID>uuid:4C39D5585706DC11B56B90D9F510219F</stRef:instanceID>
<stRef:documentID>uuid:1BB542315206DC11B56B90D9F510219F</stRef:documentID>
</xapMM:DerivedFrom>
PICT16 from Raj<xapMM:DerivedFrom rdf:parseType="Resource">
<stRef:instanceID>uuid:4A39D5585706DC11B56B90D9F510219F</stRef:instanceID>
<stRef:documentID>uuid:19B542315206DC11B56B90D9F510219F</stRef:documentID>
</xapMM:DerivedFrom>
PICT17 from Raj<xapMM:DerivedFrom rdf:parseType="Resource">
<stRef:instanceID>uuid:426E2C450D07DC119FD78ABD8FA3219B</stRef:instanceID>
<stRef:documentID>uuid:1D57A31D0307DC119FD78ABD8FA3219B</stRef:documentID>
</xapMM:DerivedFrom>
PICT18 from Raj<xapMM:DerivedFrom rdf:parseType="Resource">
<stRef:instanceID>uuid:DA6B83F81407DC119FD78ABD8FA3219B</stRef:instanceID>
<stRef:documentID>uuid:5E65D66D1307DC119FD78ABD8FA3219B</stRef:documentID>
</xapMM:DerivedFrom>
What we can see now that at least, those Pict as been saved at least two time, and the last time with Photoshop.
Hope I made a mistake somewhere...

What's your opinion about all that ?
Gfamad