HELP needed with damaged CRW files

[NickSmith]

I'll take all the normal comments about backing up and not deleting the files in the first place as read and they are all correct, but.....

I have (accidentally) deleted a whole load of images, unfortunately, unarchived, all CRW files - (it's a long story but I blame it on Adobe Bridge...)

I have run a number of standard file recovery utilities, and have actually recovered the vast majority of the lost data (some off the original CF card which had only partly been re-used, and some off the hard disk), but as is normal in these cases, the photos I really wanted (of my wife's PhD graduation ceremony) havn't been so cooperative.

I have recovered some files, they appear to be of a reasonabale length, but no software that I have tried can process them. I've tried BreezeBrowser, Adobe CS2 and even the original Canon utility. So obviously, in some way the files have been corrupted.

Now I know that there are two images stored in the file, the CRW raw data. plus a medium res. JPEG file. I am hoping that even if important data in the file is missing, that the image data is still there and retrievable in some form.

Does any one out there have any experience with delving into the intricacies of the CRW files format. Does anyone have any suggestions?

I have found some web sites which document the files format, and if necessary I will write some C code to help me try and recover the data, but if someone has already done this, all the better.

In hope

Nick:(

[Chris Breeze]

I'm sorry I don't know of any software for recovering corrupted CRW files. The CIFF format used for CRW files uses a pointer at the end of the file to offset into the varous data heaps and so if the file has a few extra bytes it may be unreadable but can be repaired by trimming of the extra bytes. You may be able to work recover the files by comparing them with uncorrupted files and reading Canon's out of date CIFF spec (assuming it is still available on the web somewhere). Otherwise you could probably recover the embedded JPEG preview.

[NickSmith]

Thanks for the comments Chris

Out of the 8 recovered but "damaged" files I managed to get some results from two of them.

As you suggested I read up on the CIFF documentation and using a known good file I managed to work out the formating of the pointers etc to the different images types.

In one image I was able to identify that the JPEG image was intact but the RAW data was corrupted - So I just replaced the corrupted start of the file with the data from another good file, recalculated the pointers and hey presto I could used BreezeBrowser to extract the embedded JPEG.

On the second file, it was the opposite way around, the raw data was intact but the JPEG and image parameters were corrupted. Again I replaced this corrupted data with that from a good file and hey presto I could process the raw and get the image - I could even use breezebrowser to "replace" the jpeg with rendering of the Raw data so that BreezeBrowser shows the correct preview.

Unfortunately the other 6 files were too far corrupted (each appeared to have good raw data, but when I tried the above process, I could only get a black picture! so I assume the RAW data was to far gone...)

Suffice it to say, I don't intend to have to do this again!!! - and I would not recommend this as part of anyones workflow!

As a post note - this all happened when I was playing around with Adobe Bridge, I thought I was deleting a shortcut to my "Pictures" folder, but I was in fact deleting the folder itself. What is disturbing is that the "Recycle Bin" wasn't used, and normally if the files/folders being deleted are to big for the recycle bin, Windows warns you and prompts for an additional confirmation. No such thing happened. I can only assume that Adobe don't use the normal Windows methods for deleting files. I have found some entries in the Adobe forums where others have found this problem - deleted files not appearing in the recycle bin. Ho hum

Nick