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BOOT CAMP 226 (21/05/02)
RECOVERING LOST IMAGES
If you think a crashed or unresponsive PC is scary, just wait
until you get a ‘corrupt data’ message on your shiny new digital camera (DSC),
ten minutes after filling the memory card with several dozen once-in-a-lifetime
photographs…
The memory cards used in digital still cameras, be they of
the Compact Flash, SmartMedia, MMC or Memory Stick variety, are generally quite
reliable but they’re not immune to Murphy’s fifth Law -- ‘if anything simply
cannot go wrong, it will anyway’ -- and sooner or later it will happen to you,
so it’s as well to be prepared, and know what to do about it.
Time for some good news, unless the card has been physically
damaged, dropped on the barbecue or fallen into a vat of acid there’s a good
chance that much of the data it contains will be recoverable, provided you don’t
do anything rash. At the first sign of trouble, such as a badly distorted image
appearing on the camera’s monitor screen after a picture has been taken, or any
kind of error message concerning the memory card, do not take any more
photographs! Incidentally, always have a spare card or two handy, just in
case.
There is a very small chance that the failure or error
message might be caused by dirty contacts on the card so give contacts a gentle
wipe with a soft cloth or dust them off with a clean, dry brush. Avoid using any
chemicals or abrasives, as this will only make matters worse.
You might be lucky but according to data recovery experts the
relatively crude filing systems used in many digital cameras are the root cause
of a lot of problems. These days virtually all DSC’s use the PC-based FAT 16 or
32 (file allocation table) filing systems but for obvious reasons the
electronics and software used to read and write files in the camera are a great
deal simpler than those found in a PC.
Most non-hardware related problems fall into two categories.
The first is the so-called ‘avalanche effect’, which happens when a relatively
small error develops in one file – the card is removed whilst the camera is
still switched on, for example – and rapidly spreads to all of the other files
on the card. The other common cause of failure is when the card is frequently
taken out of the camera and loaded into a USB or PC-Card reader -- connected to
a desktop or laptop PC -- and Windows Explorer is used to delete, move and copy
files. This is a perfectly legitimate
use for a memory card, as far as the PC’s filing system is concerned the card is
just another disc drive, but changes made to the cards filing structure can
sometimes confuse the camera.
In cases where a PC reader cannot access a memory card you
can sometimes copy images to the computer using the camera’s serial or USB
cable. By the way, you can avoid this kind of thing happening in future by
completely erasing and reformatting memory cards in the camera after every few
sessions.
If basic techniques have failed then it’s time to bring in
the big guns in the shape of data recovery companies or specialist software. The
former option is worth considering if you are a complete novice, you’re
unwilling to take the small risks involved in DIY data recovery, or your own
attempts have failed but be warned that a favourable outcome is by no means
guaranteed, and it can be very expensive. Just type ‘memory card recovery’ into
your favourite search engine for a list of companies, and get several quotes.
Step one in DIY recovery is to try and copy the data from the
card to a folder on your PC so you can safely experiment with the copied data
and the original files are preserved. Depending on the degree of corruption this
may not be possible and it’s not unusual for Windows Explorer to be able to read
the contents of a card but refuse to copy it. Even if the data is complete
gobbledegook check the size of the files, the larger they are the better the
chances of recovering complete images. It’s a bit of a long shot but you can try
opening files using Windows Paint or any other picture and image editing
software on your PC but don’t expect miracles.
Before you give up or call in the experts try and reconstruct
the data using specialist data recovery software. There is plenty to choose
from, have a look at PC Inspector (http://www.pcinspector.de/
smart_media_recovery/uk/demo.html)
and PhotoRecovery (http://www.lc-tech.com/photorecovery.asp)
but my personal favourite is PhotoRescue, which is available as a shareware demo
from: http://www.datarescue.com/photorescue/.
Unfortunately it only works on Windows 2000/XP, but a MAC (OS X) version is also
available. The demo will show you if there are any recoverable pictures on the
card in the form of thumbnail images. If so you can pay the licence fee ($29)
and you’ll be sent the unlocked version of the program by email. This will allow
you to recover and save the full image files as regular JPEG files.
PhotoRescue is slow but methodical, rebuilding the files on a
64Mb card can take upwards of a couple of hours, even on a 1GHz machine, but if
there’s anything on the card it will find it; it even managed to recover several
pictures on one of my corrupted cards that had been deleted, after the card had
been formatted!
Next week – Managing Windows start-up
JARGON FILTER
JPEG
Joint
Photographic Experts Group – ‘lossy’ file compression format, used for storing
photographs and transmission over the Internet
MMC
MultiMedia Card, postage-stamp sized memory card used in
digital cameras and MP3 music players
USB
Universal
Serial Bus, high-speed serial connection system for PC peripherals
TOP TIP
A few weeks ago in Boot Camp we showed you how to put the
very useful ‘Work’ menu onto the Word toolbar, but omitted to tell you how to
remove entries, so in response to many emails here’s how, but first, to recap.
The Work menu gives
single-click access to selected documents. To install it right-click in an empty
area of the toolbar, select Customize, then the Commands tab, scroll down the
Categories list, select Built In Menus, go to the Command list, scroll down to
Work then drag and drop it on to a toolbar. To include a document on the menu
open it and click ‘Add to Work Menu’. To remove an entry press
Ctrl + Alt + - (hyphen), the cursor changes to a bar, go to the Work menu and
click on the item you want to delete.
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