CHDK Forum

Using CHDK => RAW Shooting and Processing => Topic started by: tuffshed on 13 / February / 2009, 19:24:34

Title: CHDK CRW and white balance
Post by: tuffshed on 13 / February / 2009, 19:24:34
I've been cruising this forum looking for answers and I think I found them, but I'm hoping I'm wrong because it seems impossible to do what I came to CHDK to do.... Maybe some of you can answer these questions directly...Here goes...

I'm an underwater photographer with an A640. I've been using manual white balance with mixed results. When I heard of CHDK and it's ability to shoot raw I thought my problems were over.  Now I can't seem to process the .CRW or .CR2 images for white balance, in fact they won't even load in standard Canon Software, DPP for one.  I've used various levels, 3.5.2 being the latest, no dice. The reason I want to use something like DPP is that they have a white balance dropper, an invaluable tool for the crazy white balance you get with underwater shots.

So I heard through this forum (and correct me if I'm wrong) that :
1. CHDK CRW is not like Canon CRW...WHAT...REALLY, what is the sense in that, why not make it exactly the same?
2. CHDK CRW doesn't store white balance info? I found this in one post, don't know what that means, raw is raw, right?

Bottom line is, I'd like to process my CHDK CRW (or CR2) files with some sort of processor that has a white balance dropper like DPP.  I've looked at a few solutions, they don't have the white balance dropper like DPP or my Olympus raw converter.

So the real question is, How can I get my CHDK CRW to look like real Canon CRW so DPP can read them, or is there a particular version of DPP that will work, failing that, what processor has a white balance dropper that can read CHDK CRW?

Thanks in advance,
- Mike (aka tuffshed)
Title: Re: CHDK CRW and white balance
Post by: wontolla on 13 / February / 2009, 20:04:18
Quote
it seems impossible to do what I came to CHDK to do....
No no! Just read a little bit more and you will be a happy costumer at the end of the day.

http://chdk.setepontos.com/index.php/topic,1532.0.html (http://chdk.setepontos.com/index.php/topic,1532.0.html)

http://chdk.setepontos.com/index.php/topic,1390.0.html (http://chdk.setepontos.com/index.php/topic,1390.0.html)

Once you convert the CHDK RAWs to DNG (or obtain DNGs straight from the camera), you'll be able to open them in your favourite software and do the white balance thing.
Title: Re: CHDK CRW and white balance
Post by: tuffshed on 13 / February / 2009, 21:49:19
Quote
Once you convert the CHDK RAWs to DNG (or obtain DNGs straight from the camera), you'll be able to open them in your favourite software and do the white balance thing.


Hmmm, I see that I have a "DNG format" checkbox in my CHDK for my A640, but when I try to check it, it complains "Cannot load CHDK/badpixel.bin Please run CHDK/SCRIPTS/TEST/badpixel.lua".  So I'm game, I try to load it, when I press Alt or shutter it takes a picture then processes for a long time, but still won't let me check that darn "DNG format" button.   Am I to conclude then that my A640 won't take DNG format, so I have to take CRW, then convert them to DNG, then try some other processor (since DPP won't accept DNG)?   Why so complicated? 

So the original question still stands : What processor will take CHDK CRW or CR2 AND contains an white balance dropper?

I've tried so far, DPP 3.5.2, Lightbox, Adobe Photoshop 7.0, Paint Shop Pro 8, Canon Raw Image Converter2, no dice.

I'm about to download and try the following, but it would be easier if someone just told me the do/do not have white balance support:
Picassa
UFraw
FixFoto
RawTherapee
DPP 6.4.1 (someone on the forum claims the Rebel 300D works, and this is the version for it)

Any others?

- Mike

Title: Re: CHDK CRW and white balance
Post by: tuffshed on 13 / February / 2009, 21:55:37
DPP 6.4.1 doesn't work
Title: Re: CHDK CRW and white balance
Post by: whim on 13 / February / 2009, 22:12:08
badpixel.lua should take 2 pics, let it run until it says ***FINISHED***

HTH,

wim
Title: Re: CHDK CRW and white balance
Post by: reyalp on 13 / February / 2009, 23:57:45
So the original question still stands : What processor will take CHDK CRW or CR2 AND contains an white balance dropper?
Please read the threads wontella linked.

CHDK raw isn't actually CRW or CR2 format, regardless of extension. As you would know if you had read the threads, CHDK raws are just a dump of the sensor data. Programs such as dng4ps and dcraw understand CHDK raw, and handle the white balance issue in various ways. Programs that expect actual canon CRW/CR2 files will not work on CHDK raw. CHDK (confusingly) re-uses the extensions because it makes deletion and USB transfer more convenient.

In general, a raw workflow will require additional effort and understanding. Unless you actually need the small increase in dynamic range, you are probably better off sticking with camera jpeg.

edit:
I guess doing your own white balance is a valid reason to use raw too, but then you need to understand the process.

ufraw has a white balance dropper, and understands both chdk CRW and DNG.
Title: Re: CHDK CRW and white balance
Post by: tuffshed on 14 / February / 2009, 19:09:49
Bingo !  Ufraw (along with the Gimp support) works on CRW and CR2 files generated by CHDK.

More importantly, it has a white balance dropper that will work fairly well for underwater white balance work.   

I have been generally able to take good pictures and am pretty adept at JPEG manipulation with Paint Shop Pro and Adobe Photoshop, but white balance on ambiant light underwater photos is a real bugger to get right.  I generally have no need for raw, as long as I properly expose the picture, but in underwater shots you can change depths a few few, or clouds could go overhead for just a second and the white balance will be radically different. Raw is the only way to go, and now I can do it with my Canon A640 instead of having to house (and worry about) a much more expensive DSLR.

Thanks again.
Title: Re: CHDK CRW and white balance
Post by: ragustin on 18 / March / 2009, 06:07:12
I tried shooting RAW with my S3IS. When I opened the RAW file in UFRAW. It says it cannot load CAMERA WB. Why is this so? How could I correct this? I need some of my images use the WB when I'm shooting because some of the photos I took is set to use CUSTOM WB.



Title: Re: CHDK CRW and white balance
Post by: fe50 on 18 / March / 2009, 07:58:36
Hello & welcome, ragustin !

I tried shooting RAW with my S3IS. When I opened the RAW file in UFRAW. It says it cannot load CAMERA WB. Why is this so? How could I correct this? I need some of my images use the WB when I'm shooting because some of the photos I took is set to use CUSTOM WB.

The CHDK RAW format is still a sensor data dump without additional informations, it doesn't contain WB data.
You can't "correct" this for RAWs.
You can enable & use the DNG RAW format instead; i'm not 100% sure about this, but: the DNG's do not have the camera's WB setting, they only have one fixed WB profile...

You can adjust the WB / color profile manually in UFRAW, save the settings & then you can load it (or use it in a batch job) for all images with the same settings...
Title: Re: CHDK CRW and white balance
Post by: ewavr on 18 / March / 2009, 08:09:07
the DNG's do not have the camera's WB setting, they only have one fixed WB profile...

CHDK DNG contains camera WB setting; even custom WB can be transfered to RAW converter (I tried ACR and dcraw).
Title: Re: CHDK CRW and white balance
Post by: fe50 on 18 / March / 2009, 08:21:15
CHDK DNG contains camera WB setting; even custom WB can be transfered to RAW converter (I tried ACR and dcraw).

Great, my brain was a bit outdated  :-X

Quote
Revision 669, 15.4 kB (checked in by phyrephox, 2 months ago)

DNG: now the whitebalance of the DNGs should match much better to the jpg than before!!! (Actually, the "as shot" whitebalance now is set in the dng exif tags, taken from the camera in a magical way, so programs like Adobe Lightroom can interpret these correctly)
(uncommented EWAVR'S code, send the money to him :D) read about it here: http://chdk.setepontos.com/index.php/topic,156.msg27215.html#msg27215 (http://chdk.setepontos.com/index.php/topic,156.msg27215.html#msg27215)