Trying to recover CR2's that are corrupted- step by step help?

[robots4joey]

Hi All,

I am pretty desperate for help as I have about 100 wedding pictures (Taken with 5d mk2) that are unreadable due to some kind of corruption. I was able to get the EXIF data from these images fine drag-and-dropping to the exiftool(-k).exe, but I want to recover the files if possible, or at least the jpeg previews.

I have no idea what perl is  and so I am at a loss for how to do what is described here: https://exiftool.org/forum/index.php?topic=4422.0

I could really use a step by step on what to install where, then what order to input values in. So far I installed Activeperl, but I don't know what to do with it.

Thank you so much for the help! If someone can help me save these photos, I will be forever grateful!!!!!

[Phil Harvey]

You've got ActivePerl installed, so let's test to be sure it works:

1) From the Windows "Start" menu, run "cmd.exe".

2) In the window that opens, type "perl -ver".  If Perl is properly installed, this should print your Perl version number.

To extract the previews:

1) Install exiftool for command line use (follow steps 1 to 4 here).

2) Put the CR2 images in a directory that is easy to find from the command line. (something like C:\images for example)

3) type this in the cmd.exe window:

exiftool -previewimage -b -w _preview.jpg -ext cr2 c:\images

This should create a set of files with names ending in "_preview.jpg" in the same directory as your CR2 images.

If this doesn't work because the metadata is corrupted, you might have to resort to trying the "extract_preview" script described in the thread you referenced, but this will require a bit more work.  Hopefully the above technique will do the job.

Recovering the RAW image is a different story.  If you send me a sample I can take a look to see if I think this is possible.  My email is philharvey66 at gmail.com

- Phil

[robots4joey]

Thank you for the help! I was able to run the cmd line you sugggested:
exiftool -previewimage -b -w _preview.jpg -ext cr2 c:\images

It worked on the good raw files, but returned gray images with colorred horizontal lines on them for the bad ones. Can you give me a little more detail on the extract preview option?

[Phil Harvey]

OK, here you go:  (this will actually use the ActivePerl you installed...)

1) Download and expand the full ExifTool distribution (Image-ExifTool-#.##.tar.gz) on your Desktop

2) Download and expand extract_preview.tar.gz from here.

3) Move "extract_preview" into the Image-ExifTool-#.## folder on your Desktop.

4) In a "cmd.exe" window, type these two commands:

cd Desktop\Image-ExifTool-#.##  (replace "#.##" with the version number of the exiftool you downloaded)

perl extract_preview c:\images

With any luck this will allow you to salvage some JPEG's from the corrupted CR2's.

- Phil

[robots4joey]

Once again: Thank you so much for the help!!!

This did create 160x160 thumbnails of the images, so I can see what they look like! But they are very very small, how can I make it output a full-resolution preview?

[robots4joey]

this command did make full resolution previews of some of the old cr2's that weren't corrupted... so am I out of luck if this doesn't work? what about trying to extract the raw data instead of the jpeg data?

[Phil Harvey]

The extract_preview script does a brute-force scan of the entire file and saves the largest JPEG that it finds.  If it only saved the small thumbnail, then it is likely that the large preview has been corrupted.  I'm guessing that the raw data is probably corrupted too, but recovering this would be very difficult even if it isn't.

But if you email me an image I'll take a look and see what I can do.

- Phil

[robots4joey]

I'll definitely send you an email with a file, they're big, like 31mb. is that ok? If you email me at: robots4joey-1@yahoo(dot)c0m, I will reply with a CR2

Thanks again for all the help!!!

[Phil Harvey]

For anyone following this thread: The raw image data was not recoverable in this case because it had been set to all zeros in the files I received.  In fact, the whole file was just zeros from about the middle of the preview image to the end.

- Phil

[robots4joey]

Thank you Phil for all your assistance!

I sent the card off to LC Tech, at the recommendation of Sandisk themselves. I hope they will somehow be able to find something, but from your assistance with delving into the actual data in the files, I am fairly certain they won't.

Thank you again!

[Phil Harvey]

If it was just the file allocation table that got messed up it is possible that the raw data still exists on the card.  I'll keep my fingers crossed for you.

- Phil