RAW Conversion with The Gimp (Linux users please help!)

I'm having a terrible time with some of my RAW images.

When I convert them.. they lose saturation.. get darker.. lose sharpness etc.

The only thing I can figure out is it must be a setting in the UFRAW plugin I use for The Gimp to convert from raw to jpg. But I can't figure what setting it would be in that case?

So I find myself constantly 'fighting' to make my images at least resemble the excellent quality they had as raw images!

Help please? Feel free to ask more questions to understand the problem, and if anybody wants to help I'd be glad to send you a RAW image for conversion.

Thanks in advance,
~Rae~

If you are able to, try digikam for conversion and compare with the output from gimp.

I actually do have digiKam and was seeing even worse washed out results from them. It seems like there must be some kind of auto conversion settings that need to be turned off or something.. but I can't figure out how to do that?

removed

I don't have Linux installed at the moment but I do use the GIMP with UFRAW. Are you saying that the images look fine in the UFRAW preview but when you click the okay and it opens in the GIMP it looks off? Or are you comparing to the embedded JPEG?

If it is the latter than I may be able to offer some help. If it is the UFRAW preview being completely different from the converted image then the only thing I can thing of is that you are using the wrong profile. Try just using sRGB throughout.

UFRAW/dcRAW doesn't offer inbuilt sharpening like ACR (Adobe Camera RAW) or DPP. You will need to use the GIMP to sharpen after the conversion.

e-k

Actually it looks okay.. if I preview the RAW image in Digicam, but whether I try to do the conversion in Digicam or The Gimp/ UFRAW the image that comes up for conversion (the file you 'edit' to be converted') looks way off.... and if you convert that file as is.. it'll convert to a poor looking jpg.. having lost a lot of saturation.. color etc.

Well ...... hmm I seem to be able to just about 'fix' them using the Exposure compensation now. I've noticed it seems to 'remember' between files what the last file's exposure adjustment was.. and I'm beginning to think that's the main problem. There is an 'assumption' in the UFRAW program that the next file will need the same adjustments... and hence things tend to look poorly since they don't.

But I guess back to the original issue..... is there anyway to see the file persay 'untouched' by adjustments within UFRAW? Sometimes I'd like to use it exactly as it was taken in the RAW format.. without making huge adjustments..

If you use digikam or krita I believe 16 bit is not a problem unlike gimp.

Checkout this screenshot of the digikam converter

http://www.digikam.org​/?q=node/101

The dropdown that says presets does it not contain an option for 'as shot' or soemthing like that? I am not at home so I cannot verify but I thaught it did.

sonshine_rae wrote in post #3289413
Actually it looks okay.. if I preview the RAW image in Digicam, but whether I try to do the conversion in Digicam or The Gimp/ UFRAW the image that comes up for conversion (the file you 'edit' to be converted') looks way off.... and if you convert that file as is.. it'll convert to a poor looking jpg.. having lost a lot of saturation.. color etc.

Okay that makes some more sense then. I haven't used Digicam so I can't speak for it but UFRAW doesn't get the camera curve as a starting point. So unless you have downloaded some curves it will appear a little odd. You can try downloading some curves (there are a few links on this page http://ufraw.sourcefor​ge.net/Guide.html).

For me, I tend to just grab a point on the top right corner and drag it left and down a bit. I may also adjust the exposure a little as well.

I've attached a sample of the curves I use -- just rename them from .txt files to .curve files.

If your colours are looking a little subdued then you can try the "use colour matrix" on the colour tab (if that option is available to you). It may be a little over the top though. Also, if you had say a +2 on saturation for your camera settings then this is what you will see in the preview image as they generally use the embedded JPEG. As a result you need to boost the saturation in UFRAW to make it look the same.

You can also set the input profile to one you have copied off of your Canon CDs (you can find information on this at http://www.maashoek.nl​/color_profiles.html and http://staffwww.itn.li​u.se …ufraw_with_cano​nSLR.xhtml). Personally, I leave the input/output profiles as sRGB.

sonshine_rae wrote in post #3291657
Well ...... hmm I seem to be able to just about 'fix' them using the Exposure compensation now. I've noticed it seems to 'remember' between files what the last file's exposure adjustment was.. and I'm beginning to think that's the main problem. There is an 'assumption' in the UFRAW program that the next file will need the same adjustments... and hence things tend to look poorly since they don't.

You're right. Generally the assumption works out okay. On the UFRAW site I think the have a page that deals somewhat with this and how to work around it.

Within UFRAW, no. I think the 'untouched' image you're referring to is the embedded JPEG. This has already been converted from RAW to JPEG by the camera's built-in facilities. Unfortunately UFRAW, unlike Canon's DPP, is not privy to the algorithms used to convert RAW files to JPEG in camera.

e-k

Sathi wrote in post #3291761
If you use digikam or krita I believe 16 bit is not a problem unlike gimp.

Checkout this screenshot of the digikam converter

http://www.digikam.org​/?q=node/101

The dropdown that says presets does it not contain an option for 'as shot' or soemthing like that? I am not at home so I cannot verify but I thaught it did.

That looks like it is presets for White Balance. The "As Shot" is available in UFRAW as well (although I believe they call it "Camera WB"). It looks like digikam uses the same base as UFRAW which is dcRAW.

16 vs 8 bits should not generally be a problem unless you are doing substantial editing after the conversion. A colour profile mismatch could cause the saturation issue, but by default UFRAW (and the GIMP) uses sRGB.

e-k

I just noticed this at the UFRaw site in the note about version 0.11:

"Give the correct camera exposure by default for Canon DSLRs. Until now raw images from these cameras came out under exposed."

So if you are using 0.10 or earlier you may want to try upgrading.

e-k

E-K thanks! ... I had to dig around a little bit but finally saw the version of UFRaw we are using is .10 .. I'll have my husband upgrade it for me.

Thanks everybody for taking the time to help me out. I am getting much better results.. as I keep trying different things anyway.

sorry i know this isnt an optimal solution. but wine + photoshop ?

i broke my windows install on my laptop recently so I havent left linux for a couple week haha.

Jejunum wrote in post #3309248
sorry i know this isnt an optimal solution. but wine + photoshop ?

i broke my windows install on my laptop recently so I havent left linux for a couple week haha.

CS2 runs pretty good under wine now...I gave up on that though and use CS2 with a vmware session. It runs suprisingly fast.

I know my husband isn't to fond of wine, plus I haven't got the funds to get photoshop though .. so Gimp it is for me.

Thanks anyway.