Unable to open DNG file

Software darktable
1

Today I tried to open few old DNG files taken using Pentax K3. DT 4.2.2 could not open DNG files. Default viewer of Win10 was able to open the original DNG files.

I converted the DNG file once more in to DNG file, using Adobe’s convertor tool. DT was able to open these new files successfully. Should I convert every image? Is there any better solution?

In the Adobe tool, I choose “no compression” & “camera raw 2.4”. Should I select latest camera raw version??

Thanks

2

what is the error message when you try and open the file?

3

You should upload a sample file here.

4

Thanks for your responses.

1) Error shown in DT
The error is
“darktable could not load xxxx.dng, switching to light table now.”
"please check that the camera model that produced the image is supported in darktable"

2) Faulty image

K3_3877{40a9575e-f471-4f71-af88-6a835e6f2d84}_1.dng|attachment (28.3 MB)

I am attaching DNG that gave the error, please take a look.

3) ExifTool opening faulty DNG file
ExifTool shows the meta data properly, but gives an error when I try to export the metadata.

image
image1903×1007 313 KB

image
image1685×1015 285 KB

Thanks

5

What I got when I run $ darktable -d camsupport

[rawspeed] (K3.dng) void rawspeed::AbstractDngDecompressor::decompress() const, line 217: Too many errors encountered. Giving up. First Error:
rawspeed::JpegMarker rawspeed::AbstractLJpegDecompressor::getNextMarker(bool), line 290: (Noskip) Expected marker not found. Probably corrupt file.

@kmilos , do you know?

RawTherapee accepts the file.

6

Rawspeed is very strict when it comes to spec compliance, and it that sense, the file is invalid.

See also Leica M10 support (0.3% of my images can't be loaded) · Issue #11695 · darktable-org/darktable · GitHub

This should be reported to Pentax, if it keeps happening with the latest firmware and a good SD card.

2 Likes
7

Can confirm that the file cannot be opened in darktable master.
Funny enough DPreview’s K3 file can.
So can the files from my k200d and my K1.
The file opens just fine in rawtherapy.

8

It kinda sounds like a traditional case of bitrot.
Does that happen with a new file straight out of the camera,
copied via a known-good SD card (or better yet, card-less tethered shoot or something)?

9

I have multiple pentax cameras; I only save files as DNG; never had any problems with darktable opening files. Maybe a bad sd-card? reformat in camera and try again.

10

Thanks everyone. Some DNG files do not have this issue. May be problem is limited to specific firmware version of Pentax K3.