Processing M246 files with dcraw or imagemagick

[wintoid]

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Hi,

 

I've been trying to make tiff files from the monochrom 246's DNG files, but it looks like dcraw and imagemagick won't correctly convert the data.  With the default settings, I get two adjacent cropped versions of the original image, and a bar of black at the bottom.

 

See example:

 

L3030134 by Simon Pietroni, on Flickr

 

Anyone know how to resolve this?

 

Thanks,

 

Simon

Edited April 24, 2018 by wintoid

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[jaapv]

Actually, a DNG is very close to a TIFF file. For instance, Rescue Pro renders .DNG as .TIF and you only have to change the extension to make them readable.

 

Anyway, there are some DNG --> TIFF converters, like this one:

 

 

https://www.onlineconverter.com/dng-to-tiff

 

Google is your friend

 

Remains the question: why should you want to do this?

[wintoid]

 

Remains the question: why should you want to do this?

 

It's a good question.  I'm interested in trying non-Lightroom software for processing M246 files, such as DXO Optics which doesn't support non-RGB files.  I thought perhaps I could write a script to convert to tiff using dcraw, then process in DXO.

 

Another ideal solution would be if I could somehow get Adobe DNG converter to convert the M246 DNG into an RGB DNG, which could then be used in DXO.

[jaapv]

Could this be of help?

 

https://www.adobe.com/support/downloads/dng/dng_sdk.html

[wintoid]

Ooh thanks Jaap, I'll take a look.

 

I've found a few more things out.  I believe this is a bug.  RawTherapee uses dcraw and shows the same behaviour.  It works fine with the sample DNGs I downloaded before I bought my camera, but doesn't work with the DNGs I am producing.

 

I believe either it's the DNG compression, or perhaps the firmware version (I updated to the latest).

[wintoid]

OK I tested DNG with and without compression.  It's fine without compression but goes wrong once compression is turned on.  I might contact the author.

[jaapv]

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There are a number of variations of DNG, Leica uses a rather obscure version (at least for the Monochrom1) called linear DNG. It is not widely supported.

 

https://www.adobe.com/content/dam/acom/en/products/photoshop/pdfs/dng_spec_1.4.0.0.pdf

 

http://www.barrypearson.co.uk/articles/dng/linear.htm

[wintoid]

Again, my thanks.  I've also just run a compressed M246 through Adobe's DNG converter (just makes another DNG using Adobe's code), and the resulting DNG can be read by dcraw.  So, like you say, Leica is using something a bit obscure here.

[Gobert]

It's a good question.  I'm interested in trying non-Lightroom software for processing M246 files, such as DXO Optics which doesn't support non-RGB files.  I thought perhaps I could write a script to convert to tiff using dcraw, then process in DXO.

 

Another ideal solution would be if I could somehow get Adobe DNG converter to convert the M246 DNG into an RGB DNG, which could then be used in DXO.

What do you mean, DXO doen’t support non-RGB files? It does.

[wintoid]

What do you mean, DXO doen’t support non-RGB files? It does.

 

Fair enough, I suppose my comment is inaccurate.  It definitely doesn't work with files from my M246 though.  I don't see either of the Leica Monochrom cameras on the supported list.

[Gobert]

Clear. I didn’t know that. I’m working with both DxO and C1 to develop M10 files. I prefer DxO above C1, although the latter is better if you need to “ rescue” files.

[Genn]

If you use Mac OsX - you could try a Raw Photo Processor. It is not an easy program to convert image files, however they do not perform demosaic calcs on monochrome raw file from Mm of M246, 

[robgo2]

ON1 Photo RAW does very well with DNG files from the M246. I think that it is an excellent image editor overall.

 

Rob