11 Jan
2008
11 Jan
'08
10:57 p.m.
Hello,
I have been asked by a friend for help with an SD-Card which apparently
is corrupted, to rescue the 120 pictures stored on it , if possible.
Apparently, the camera repeatedly asks the user if it should or not
reformat the card.
So I first tried to mount that card into my system, using an USB card
reader. Unfortunately, I found no matching filesystem to do so; in
/var/log/messages, I found errors like :
Jan 11 22:12:55 niepce kernel: FAT: invalid media value (0x3f)
Jan 11 22:12:55 niepce kernel: VFS: Can't find a valid FAT filesystem on
dev sdf
So, the filesystem obviously seems to be damaged !
Then, I tried reading out the card with dd into a file, which gave me,
as expected, a 256 MB file:
dd if=/dev/sdf of=/data/tmp/secdig.dat
In this file, I searched for typical data like dates or other typically
EXIF data, which brought partial results:
hexdump -C secdig.dat | grep 2007
0290c0c0 56 65 72 2e 31 2e 30 20 20 00 32 30 30 37 3a 30 |Ver.1.0
.2007:0|
0290c350 d0 07 00 00 1c 00 00 00 0a 00 00 00 32 30 30 37
|............2007|
0290c370 32 30 30 37 3a 30 38 3a 31 39 20 31 30 3a 32 39 |2007:08:19
10:29|
02920070 48 59 7e 64 27 a6 e5 ef 5d d8 55 08 cd c9 f5 32
|HY~d'...].U....2|
02a20070 97 12 ea 1a 8e 8f 36 a1 bf 5f b2 68 de 58 e3 96
|......6.._.h.X..|
02ab80c0 56 65 72 2e 31 2e 30 20 20 00 32 30 30 37 3a 30 |Ver.1.0
.2007:0|
02ab8350 d0 07 00 00 1c 00 00 00 0a 00 00 00 32 30 30 37
|............2007|
02ab8370 32 30 30 37 3a 30 38 3a 31 39 20 31 30 3a 33 35 |2007:08:19
10:35|
After comparing some data to intact pictures of my own, I noticed that
the data seemed to represent intact picture data, as far as the Exif
part of the pictures is concerned, the actual picture data being of
course uninterpretable.
Now, I would be very grateful if somebody could give me any hints how I
could possibly recover the image data contained in the dump or if there
is any way to use these data in a way that would enable me to get back
the data.
Any help will be greatly appreciated.
TIA
Jean-Jacques Mouris