Author Topic: Corrupt images help  (Read 5308 times)

luke1100

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Corrupt images help
« on: April 21, 2015, 06:12:44 PM »
I came home with images of my wife visiting her childhood (old-school dirt) home in a small town in China, and all the images are corrupt. 

Can I:
Convert the raw to jpeg inside 5D MII (the images look okay when viewed on the 5D's screen)

Or can I rip out the imbedded jpg preview image?

chmee

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Re: Corrupt images help
« Reply #1 on: April 21, 2015, 06:22:55 PM »
(a) rewriting the cr2 is not impossible, but due to lack of informations we cant say, if it works or not.
(b) those pictures shown on body-screen are already converted jpg's inside the cr2, so we cant say if convertion inside the body would work.
(c) is there any setting inside 5D II to convert once again to jpg? i dont know..
(d) there are numerous apps to extract the jpg from cr2 - these should work by now - as far as i can assume your problem

regards chmee

luke1100

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Re: Corrupt images help
« Reply #2 on: April 21, 2015, 06:32:34 PM »
There aren't any converting options (I've seen) in the 5D menu.  I was hoping ML had something I didn't know about. :)

Thanks, I'll look-up extraction the jpgs from the CR2 file.


a1ex

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Re: Corrupt images help
« Reply #3 on: April 21, 2015, 07:01:45 PM »
Can you also upload a CR2, to see what kind of corruption you are talking about?

luke1100

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Re: Corrupt images help
« Reply #4 on: April 23, 2015, 05:25:29 AM »
I found instructions about pulling (on camera preview image) JPGs out of the CR2 file with a hex editor.  I'll give it a try on my next day off.

I've tried formatting the CF card on the computer and in the camera and still have the problem of all images and video files being corrupt.  I guess it's a just a bad SanDisk card.

www.truetypemedia.com/_MG_9629.CR2

www.truetypemedia.com/_MG_9629_proc.jpg

//Preview removed.  Please don't post 24mpixel images to the board.  Audionut.


luke1100

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Re: Corrupt images help
« Reply #5 on: April 23, 2015, 06:00:23 AM »
a1ex, I fixed the link to the CR2 file.

a1ex

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Re: Corrupt images help
« Reply #6 on: April 23, 2015, 06:52:51 AM »
Embedded JPEG is corrupted as well.

I tried to reproduce the corruption by taking a good JPEG (also a embedded preview from a 5D2 CR2) and flipped some numbers here and there in a hex editor, without a real logic.

Result: http://a1ex.magiclantern.fm/debug/corrupted-cr2/DUAL7604.thumb.jpg

This makes me think it was a bad card.

One of those tools might help fixing the embedded jpegs:
https://www.raymond.cc/blog/repair-and-fix-corrupted-images/
http://www.jihosoft.com/free-utilities/jpeg-repair-tool.html

This tutorial might also give some hints:
http://www.cgsecurity.org/wiki/PhotoRec_Data_Carving

chris_overseas

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Re: Corrupt images help
« Reply #7 on: April 23, 2015, 07:40:19 AM »
One possibility is that there's corruption happening when you copy the photos to your PC, rather than there being any problem with the CF card itself. This could be due to a bad card reader, USB cables, or USB port. USB 2 card readers used in conjunction with UDMA7 CF cards are also known to be problematic and can even physically damage your memory cards(!).

Try copying the photos off using a different approach, e.g.via a USB cable plugged directly into the camera rather than using a card reader and see how you get on.
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Walter Schulz

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Re: Corrupt images help
« Reply #8 on: April 23, 2015, 08:01:30 AM »
USB 2 card readers used in conjunction with UDMA7 CF cards are also known to be problematic and can even physically damage your memory cards(!).

You're mixing things up. The only card manufacturer I know having compatibilty problems is Komputerbay with it's UDMA-7 cards. They make it pretty clear that those cards should not be used in cardreaders without UDMA-7. And it really doesn't matter which USB-interface is used.