[BigMackCam]

Many thanks to all who responded with kind suggestions. With your help, and some additional tests and digging of my own, I think I've found the problem - or narrowed down the possibilities, at least.

The camera that captured these TIFF files is a 2000-vintage Pentax EI-200, a joint effort by Hewlett Packard and Pentax which was also sold as the HP PhotoSmart 912. It offers two file formats, JPEG and TIFF.

Having re-formatted the card, I set the camera to JPEG capture instead of TIFF, took a couple of photos, then tried to upload and view them on my laptop using my Hama card reader. It worked perfectly - no errors from Windows Photo Viewer, and no problems ejecting the drive afterwards. So, it appeared the problem was with the TIFF files, or Windows 10's handling of them (and not the CF card or reader). I wondered if linux would have the same issue?

I set the camera to capture TIFF files, took a couple of shots, and then tried reading them in my Ubuntu 20.04 virtual machine. No problem viewing them, and no issues with ejecting the drive either. I then tried opening one of the TIFFs in GIMP and got the error message "file-tiff: Null count for 'Tag 33426' (type 4, writecount -3, passcount 1)", though it loaded and rendered the file successfully. Interesting. I also noted that the TIFF file was a two page document, the second page being a thumbnail image.

I exported the file from GIMP as a single page TIFF, back onto the CF card, then tried reading it in Windows 10, with no problems reading the file or ejecting the drive afterwards.

Digging around on the internet brought up very little, but it seems like tag 33426 is outside of the official TIFF specification, and may in fact be illegal. I found a post on one website that references this unusual tag in a file from a Kodak DC290 camera, and rather interestingly it shows the same firmware manufacturer - "Flashpoint Technology" - as my Pentax EI-200. Coincidence? I doubt it.

So, in conclusion, it seems that the process running under dllhost.exe ("COM Surrogate") to read the TIFF file is failing either because of this strange tag within, or perhaps because it's a two page document... but I strongly suspect it's the tag.

Frankly, I'd have hoped Windows 10 was a tad more robust than this. One of the frustrating side effects of the COM Surrogate failure was that the OS left the TIFF files on my laptop locked, so I couldn't delete or do anything else with them (this explains why the drive wouldn't eject). I had to restart in "Safe Mode with Command Line", navigate to the relevant directory and delete them that way, before booting back in normal mode.

My workaround - for now, at least - is to copy the camera's TIFF files to my Ubuntu VM, open them in GIMP and export them as new TIFF files. It's a bit clunky, but I don't take many photos with this camera; it's a novelty thing that I use only occasionally, for nostalgic amusement. I can live with the extended workflow

... or, I could simply shoot JPEGs. That said, the TIFFs hold considerably more information, providing greater latitude for white balance adjustments and the like. Still, I'm only using this camera for a bit of fun. Perhaps JPEGs might be the way to go.

I may try to find an alternative third-party Windows 10 codec for TIFFs... one that ignores 'invalid' tags. I don't hold out a great degree of hope, but it's worth a shot.

Many thanks again to all who responded. You good folks never disappoint

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Last edited by BigMackCam; 07-20-2021 at 02:38 AM.

[Dartmoor Dave]

That's a great piece of detective work ^ . Now when (and where) do we get to see some shots with the EI-200?

[BigMackCam]

That's a great piece of detective work ^ .

Thank you, sir

Now when (and where) do we get to see some shots with the EI-200?

Soon, and right here on the EI-200's natural home

I'm spending most of my outdoor time exercising at present, erasing the consequences of "lockdown snacking" (22lbs lost thus far, and counting...) - but I hope to get an hour or two for photography this week...

[Not a Number]

Interesting. What happens if you change the file association for TIFF to some third party application like GIMP or IrfanView? I have a number of multi-page TIFFs and only a few applications can handle them.

Change default apps from Settings -> Apps -> Default Apps -> "Choose default app by file type"

You can sometimes get rid of stubborn files with a utility that runs processes as Trusted Installer such as RunasTI or ExecTI.

Trusted Installer is the "God" account in Windows with even more privileges than Administrator.

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Last edited by Not a Number; 07-20-2021 at 07:48 AM.

[BigMackCam]

Interesting. What happens if you change the file association for TIFF to some third party application like GIMP or IrfanView? I have a number of multi-page TIFFs and only a few applications can handle them.

Change default apps from Settings -> Apps -> Default Apps -> "Choose default app by file type"

Sure, I could do that... however, the problem begins before even opening the files in an app. When I copy them from the card to a destination directory in File Explorer and try to eject the drive, it will now say it's busy. I think it's when Windows tries to extract or generate thumbnails for the files. Of course, I could disable thumbnails, but I'd rather not do that as I find them handy when identifying files outside of my raw processing and image editing tools.

Based on my suspicion about thumbnails, I came across this rather old but relevant post:

https://devblogs.microsoft.com/oldnewthing/20090212-00/?p=19173

You can sometimes get rid of stubborn files with a utility that runs processes as Trusted Installer such as RunasTI or ExecTI.

Trusted Installer is the "God" account in Windows with even more privileges than Administrator.

Thanks for that, I'll take a look

[Dartmoor Dave]

Sure, I could do that... however, the problem begins before even opening the files in an app. When I copy them from the card to a destination directory in File Explorer and try to eject the drive, it will now say it's busy. I think it's when Windows tries to extract or generate thumbnails for the files. Of course, I could disable thumbnails, but I'd rather not do that as I find them handy when identifying files outside of my raw processing and image editing tools.

The symptoms certainly sound like it's a problem with the thumbnails.

I always had exactly this problem with raw files from my GX-10 on Windows 7. File Explorer would slow to a crawl, the drive would report itself busy, and the only solution was to manually kill the dllhost.exe process responsible. So I just made do without thumbnails and used the free Instant Jpeg from Raw utility to extract the jpeg previews instead. I'm almost certain that the underlying problem was with the codec, because it began immediately after I installed a Windows codec pack update. So of course I uninstalled the codec pack update and then I lost ALL my codecs for everything. I ended up with no other choice than to reinstall the codec pack and llve with the com surrogate problem. Thanks Microsoft!

(Great work with the exercise regime, by the way. I could do with shedding a stone or two myself.)

[BigMackCam]

I think I may have found a possible work-around for the problem (at least so far as it applies to my specific issue with Pentax EI-200 TIFF files).

There's a free utility called ImageMagick which I'd heard of some time ago, but never used. One of its many features is image file conversion, and one of the command line options allows you to specify TIFF tags that should be ignored in processing. I'm thinking I could write a small script to read the TIFF files from the CF card, ignoring tag 33426, and output them as new TIFFs - without the troublesome tag - to a directory on my laptop.

Further investigation and experimentation required, but I think I'll install ImageMagick later today and see if it'll work as I'm hoping...

[ehrwien]

Would it be possible to upgrade the codecs needed for properly recognizing the TIFF files yourself? I remember doing that for some audio and video codecs before (though in WinXP times). Either I installed LAME for de-/encoding .MP3s and some .AVI codec pack for video files separately, or I used some software that came with those codecs already, like VLC or MPlayer. The same should be possible with image files and connected codecs? The problem would be finding the correct codec.

[AfterPentax Mark II]

Many thanks to all who responded with kind suggestions. With your help, and some additional tests and digging of my own, I think I've found the problem - or narrowed down the possibilities, at least.

The camera that captured these TIFF files is a 2000-vintage Pentax EI-200, a joint effort by Hewlett Packard and Pentax which was also sold as the HP PhotoSmart 912. It offers two file formats, JPEG and TIFF.

Having re-formatted the card, I set the camera to JPEG capture instead of TIFF, took a couple of photos, then tried to upload and view them on my laptop using my Hama card reader. It worked perfectly - no errors from Windows Photo Viewer, and no problems ejecting the drive afterwards. So, it appeared the problem was with the TIFF files, or Windows 10's handling of them (and not the CF card or reader). I wondered if linux would have the same issue?

I set the camera to capture TIFF files, took a couple of shots, and then tried reading them in my Ubuntu 20.04 virtual machine. No problem viewing them, and no issues with ejecting the drive either. I then tried opening one of the TIFFs in GIMP and got the error message "file-tiff: Null count for 'Tag 33426' (type 4, writecount -3, passcount 1)", though it loaded and rendered the file successfully. Interesting. I also noted that the TIFF file was a two page document, the second page being a thumbnail image.

I exported the file from GIMP as a single page TIFF, back onto the CF card, then tried reading it in Windows 10, with no problems reading the file or ejecting the drive afterwards.

Digging around on the internet brought up very little, but it seems like tag 33426 is outside of the official TIFF specification, and may in fact be illegal. I found a post on one website that references this unusual tag in a file from a Kodak DC290 camera, and rather interestingly it shows the same firmware manufacturer - "Flashpoint Technology" - as my Pentax EI-200. Coincidence? I doubt it.

So, in conclusion, it seems that the process running under dllhost.exe ("COM Surrogate") to read the TIFF file is failing either because of this strange tag within, or perhaps because it's a two page document... but I strongly suspect it's the tag.

Frankly, I'd have hoped Windows 10 was a tad more robust than this. One of the frustrating side effects of the COM Surrogate failure was that the OS left the TIFF files on my laptop locked, so I couldn't delete or do anything else with them (this explains why the drive wouldn't eject). I had to restart in "Safe Mode with Command Line", navigate to the relevant directory and delete them that way, before booting back in normal mode.

My workaround - for now, at least - is to copy the camera's TIFF files to my Ubuntu VM, open them in GIMP and export them as new TIFF files. It's a bit clunky, but I don't take many photos with this camera; it's a novelty thing that I use only occasionally, for nostalgic amusement. I can live with the extended workflow

... or, I could simply shoot JPEGs. That said, the TIFFs hold considerably more information, providing greater latitude for white balance adjustments and the like. Still, I'm only using this camera for a bit of fun. Perhaps JPEGs might be the way to go.

I may try to find an alternative third-party Windows 10 codec for TIFFs... one that ignores 'invalid' tags. I don't hold out a great degree of hope, but it's worth a shot.

Many thanks again to all who responded. You good folks never disappoint

Anyway, we all became wiser and learned a lot from thinking about the problem and eventually learned of your solution! Congratulations!

[Dartmoor Dave]

Would it be possible to upgrade the codecs needed for properly recognizing the TIFF files yourself? I remember doing that for some audio and video codecs before (though in WinXP times). Either I installed LAME for de-/encoding .MP3s and some .AVI codec pack for video files separately, or I used some software that came with those codecs already, like VLC or MPlayer. The same should be possible with image files and connected codecs? The problem would be finding the correct codec.

FastPictureViewer does a codec pack that might do the trick -- or might not with such an old camera as the EI-200. There's a free trial version but I should be clear that I haven't tried it myself: https://www.fastpictureviewer.com/codecs/

Edit:
I've installed the free trial version (in a vm) and it hasn't broken anything, but of course I haven't got any EI-200 TIFFs to try it out on and I can't find any online. I'd put it in the "probably no harm in trying just in case it works" category.

[ehrwien]

FastPictureViewer does a codec pack that might do the trick

The question is whether it installs the codec pack for other programs or Windows itself to use as well, or just for its own use.

But I think it was after I had installed FastStone ImageViewer (a different one; I did fancy trying FastPictureViewer for its supposedly fast browsing, but didn't do it so far), that I could preview RAW files inside of Windows folders.

So can't hurt to try.

[graemev]

Make sure you've not got one of these "Bogus cards" e.g. actual 4mb, reports as 64Gb ...I managed to buy a bunch of USB sticks like that. I reported them got my money back but kept the cards, used these to develop a program which can (destructively, needs to be reformatted afterwards) scan the cards. I'd post a copy but I see you're a windows user, so it won't work for you, I suspect similar GUI tools exist for windows.

The issue often shows up on unmounting, as that's when the data typically really gets written (even if it's only updating the last read date&time)