Interrim fix to handle monochrome cameras?

[Beep6581]

Originally reported on Google Code with ID 2017

I've looked a bit at handling B&W cameras, more specifically Leica M Monochrom and Phase
One IQ260 Achromatic.

My plan is to do something minimal, ie be able to turn off demosaicing (issue 1900)
but still handle the files internally as RGB just all channels set to the same. It
will have "strange" effects like you can set white balance and thus change the tone
of the picture, you'll still have all the color tools available although the don't
make sense, but at least you can do a proper rendering.

There will need to be some minimial patching around how to handle cameras which is
not bayer to achieve this. I'll make an additional flag in rawimage which is "isMonochrome"
to separate it more clearly so I won't look at the "isBayer" flag for this.

I know there's a long term plan to handle Foveon and Fuji Xtrans etc, but I'm assuming
it's quite far away still, and that today RawTherapee can actually *only* do bayer
sensors, and if it's not a bayer (!isBayer()) sensor sort of undefined things happen.
I thought I could make a simple patch to at least handle B&W cameras (and IR-modified
cameras etc) while we wait for some more substantial reorganization of demosaicers.

Do you think this is okay?

Reported by torger@ludd.ltu.se on 2013-10-25 06:30:36

[Beep6581]

got kind of lazy and now I'm thinking to wait until someone actually complains and wants
support for their B&W camera.

Reported by torger@ludd.ltu.se on 2013-11-05 15:19:51

• Labels added: Type-Enhancement
• Labels removed: Type-Defect

[Beep6581]

*raises hand* the possibility of using my B&W converted Nikon D40 in Rawtherapee would
be nice :) 

This is not really a complain, i can't use this fine free software, do nearly nothing
for the community and then ask for Enhancements which only serve my personal needs.

Reported by techfreak2000 on 2013-12-08 11:35:57

[Beep6581]

Hi Torger,

I'm "complaining"! Well, asking respectfully, really.

As we discussed here:
http://www.luminous-landscape.com/forum/index.php?topic=90105.msg735916#msg735916

...I showed a small section of an IR > 780nm shot with a Kodak CCD, where all 3 channels
respond identically in quantum efficiency from 820nm longwards, and very closely as
820nm is approached. So this is almost the same response as an Achromatic back (pure
mono sensor) in this wavelength regime. Therefore I think that de-bayering is not actually
needed and a sharper image could be obtained without this interpolation. Which is why
I turned it off [- which in turn is why I was so excited about the new RT being able
to turn it off!]. 

All the medium format Kodak CCD datasheets indicate this equal-response IR behaviour,
and also the Kodak CCDs for the Leica M8 and R-digital...so there would be a "market"
of users for this enhancement. 
I'd expect the Leica M9 to be the same, but I haven't seen a datasheet for its CCD.

Here's a link to a sample RAW IR file from my DCS645M - the same image I used in that
Luminous Landscape thread:

https://dl.dropboxusercontent.com/u/7418300/42GV0403.DCR

Thanks,
Ray

Reported by Ray.F.Butler on 2014-06-19 14:38:12

[Beep6581]

Reported by torger@ludd.ltu.se on 2014-06-19 18:17:30

• Status changed: Duplicate
• Merged into: #2409