Image Recovery

[AReality]

My guess is they read the analog signal from each bit location.
[previous bit value, current bit value]
A [0,0], [0,1], [1,0], [1,1] should give different voltage.
Thus given the current bit, will be able to retrieve previous bit info.

If this method is used, even after 3 bit writes may still be able to retrieve. Depends on the quality of the flash ROM used.

 

[ericp]

My guess is they read the analog signal from each bit location.
[previous bit value, current bit value]
A [0,0], [0,1], [1,0], [1,1] should give different voltage.
Thus given the current bit, will be able to retrieve previous bit info.

If this method is used, even after 3 bit writes may still be able to retrieve. Depends on the quality of the flash ROM used.

AReality, can you explain further ? I'm interested ... if I infer correctly from what you're saying, it take 3 or more overwrites before the data is completely irretrievable, is this accurate ?

 

[scud]

bro, hope to hear good news from you.

 

[espn]

Thanks scud... crossing my fingers, toes, eyes too

 

[tokrot]

Hi pal,

did you recieve the parcel? I guess no.. becoz I have copied to myself and yet to recieve it either. If you did not recieve too, why not go to MSN messenger and I will transfer directly to you?

 

[espn]

Hey tokrot, thanks for the file, I've received it actually last night, but I gave up testing and recovery. Will head down for the paid help later.

Had a lot of PMs and handphone calls regarding my data loss, appreciate it folks, esp for those whom I've even hardly spoken to before!!

 

[AReality]

AReality, can you explain further ? I'm interested ... if I infer correctly from what you're saying, it take 3 or more overwrites before the data is completely irretrievable, is this accurate ?

I'm just guessing only. Maybe they employed some alien to phychologically read the CF.

It's just like writing on a notepad with a pencil.
1st stroke can be seen.
If U rewrite that stroke, it'll appear darker than if only written with 1 stroke.
Thus reading the "darkness" of the stroke shows that whether there is another stroke under it.

 

[Zerstorer]

Unlike HDD which are magnetic media, flash memory are comprised of cells with charges stored to determine the logic level. Once the logic level is reset, I don't see how there can be any residual signal to recover from.

 

[melnjes]

Good luck espn! Keep us updated whether you can get your images back.

 

[tokrot]

Hey tokrot, thanks for the file, I've received it actually last night, but I gave up testing and recovery. Will head down for the paid help later.

Had a lot of PMs and handphone calls regarding my data loss, appreciate it folks, esp for those whom I've even hardly spoken to before!!

Sorry to hear that.. But funny thing is I did not recieve the parcel copied to myself. :dunno: Anyway, good luck in your recovery progress..

 

[AReality]

Unlike HDD which are magnetic media, flash memory are comprised of cells with charges stored to determine the logic level. Once the logic level is reset, I don't see how there can be any residual signal to recover from.

The lowest form of data storage for all storage form are not discrete of 1s or 0s, but in analog form. Reading the non-discrete values for each bit position can yield different fractional values, which in turn can be interpreted as almost '1', or almost '0'.
A bit with a previous value of 0, then overwritten by a 1, will have a non-discrete value (usually lower) than that of a previous value of 1, then overwritten by a 1.

 

[CYRN]

Date recovery is much easier on HDD because of several factors.

1. The data stream is not continous.. (even when you defrag the HDD)... so parts of the data can be recovered as it's unlikely to be overwritten if there the HDD is not filled to the brim.

2. The magnatism which represents the data is not completely "destroyed" when overwritten... there are residue traces that can be picked up by sensitive "readers"

3. As Areality mentiond the "data" retrived from those specialised readers outputs in analogue format... the threshold voltage that distinguishes the "0" and "1" can be re-defined to less tolorance.

For CF cards... they are much like RAM/ROM. Recovery is pretty slim once the "space" allocated to each bit is "re-filled"... unless they are able to detect residue voltage of the transistors or capacitor.... then again... since it's that important... no harm tyring all possible methods...

All the best.

 

[espn]

After two days of kind emails, PMs and even help offered by Eastgear and sykestang, I've come to the conclusion that I'll need to accept the fact that my images are lost, there's nothing I can do about it but to be frank with my client.

Once again, would like to thank all those who've taken time and effort to PM me, come to IRC to help me and for the best wishes you folks have given me.

Thanks once again.

 

[espn]

Thanks to ^chaotic^ who recommended me a software 2 days back (that I just made a purchase in the last hour) I managed to salvage the shots that I lost!!

The money was well spent. Now, back to my processing of images!! Thank you folks!!!

 

[scud]

good to hear tat u managed to recover the lost photos.
:sweat:

 

[mpenza]

let us in on the name of the software?

 

[espn]

eImage Recovery - http://www.octanesoft.com

Was a bit hesitative as the program only showed the icons when locating the lost file and not thumbnails of the RAW files I was shooting in (.NEF).

Seems to me that it's pretty complicated to restore the bits and pieces of NEF files that many other programs failed, except Lexar Image Rescue and Sandisk Rescue Pro which managed to retrieve at fast speed but only the more recent images instead of the older ones.

 

[AReality]

Ehhh...
To confirm, all shots that were previously overwritten, or just the 30+ few shots?

 

[tokrot]

Good to hear that u managed to retrieve your images. Understand how you felt too. I had two bad encounters which I had lost more than a total of 100 gig of harddisk data which spanned over 8 yrs of collections. This really pains me... :cry: I decided that this would never ever happen again so I bought a new DVD writer. Now using it also to back up the rest of data...

 

[Wai]

Thanks to ^chaotic^ who recommended me a software 2 days back (that I just made a purchase in the last hour) I managed to salvage the shots that I lost!!

The money was well spent. Now, back to my processing of images!! Thank you folks!!!

that's great, now with your experience and software that you have, you can start your image recovery service for pple already

thats how i learn last time also