Author Topic: Thumbnail image corruption  (Read 2329 times)

Offline Paul Smith

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Thumbnail image corruption
« on: April 10, 2008, 11:58:39 PM »
Hi,

I just started getting some weird corruption problems with some images from my last two events. Photo Mechanic is showing corrupted thumbnail images on random pictures. At first I thought it was a problem with my camera but, on checking, the images appeared fine on the camera's LCD display. I then went back to one of the corrupted images in Photo Mechanic and opened it in Photoshop and the image was fine.

On double-clicking the thumbnail in PM, the preview image at first appeared corrupted but then when PM loaded the high res file it was fine. So the problem is only with the thumbnails. I'm attaching a screenshot of the thumbnail showing the problem if that helps. Any ideas?

Cheers,

Paul

PM 4.5.3.1; Mac Dual G5; OSX 10.4.11

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Offline Kirk Baker

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Re: Thumbnail image corruption
« Reply #1 on: April 11, 2008, 06:32:23 AM »
Paul,

I just started getting some weird corruption problems with some images from my last two events. Photo Mechanic is showing corrupted thumbnail images on random pictures. At first I thought it was a problem with my camera but, on checking, the images appeared fine on the camera's LCD display. I then went back to one of the corrupted images in Photo Mechanic and opened it in Photoshop and the image was fine.

On double-clicking the thumbnail in PM, the preview image at first appeared corrupted but then when PM loaded the high res file it was fine. So the problem is only with the thumbnails. I'm attaching a screenshot of the thumbnail showing the problem if that helps. Any ideas?

Could you send us a sample image that demonstrates this problem?  Please click on my name to the left of this message.  Then click on the "personal message" link.  Send me a message regarding this issue and I'll respond with server upload info.

Thanks,

-Kirk


Offline dennis

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Re: Thumbnail image corruption
« Reply #2 on: April 16, 2008, 11:16:54 AM »
Paul,

I looked at the corrupted image of Mila Kunis (which has IPTC and XMP added by PM) compared to the original file and found that there were 11 bytes within a 4K byte block that had bits flipped.  Everything else was fine.  This occurred about 2/3 of the way through the file.  In each case, it was a single bit of a byte that went from 1 to 0, usually the first nibble and usually either 2 of the four bits (8 and 2).  This tells me you have some bad hardware, probably memory.  I'd run a memory test on your machine to see what's going on.  This is definitely not something that PM does.  I would expect you to also be seeing other problems with your machine besides Photo Mechanic.

--dennis


Offline Paul Smith

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Re: Thumbnail image corruption
« Reply #3 on: April 17, 2008, 01:41:02 PM »
Hi Dennis,

Many thanks for the info. I have been having some other problems lately with the computer. Last night I ran the Apple Hardware Test and it did indicate an error in one of the memory modules. I've removed the offending module and it's paired module and now all seems to be fine again.

Cheers,

Paul