[drndrw]

Hey everyone. I've had my K20d for a couple of months now, and I enjoy shooting everything in RAW. I love the look of my shots on my camera, but when I open them up on my Ubuntu machine for post processing, I'm not very pleased with my results (after processing). Since I'm fairly new to more serious photography, can anyone suggest any software/ tutorials for Linux based post processing software? I am currently using UFraw. Thanks so much!

[newmikey]

Hey everyone. I've had my K20d for a couple of months now, and I enjoy shooting everything in RAW. I love the look of my shots on my camera, but when I open them up on my Ubuntu machine for post processing, I'm not very pleased with my results (after processing). Since I'm fairly new to more serious photography, can anyone suggest any software/ tutorials for Linux based post processing software? I am currently using UFraw. Thanks so much!

Linux Photography
RawTherapee 3.0 alpha 1 and license changes
Flickr: G'MIC
Flickr: Linux Flickrs

And Google is your best friend, as well as internet forums and user groups plus of course the excellent documentation on the software websites themselves like rawtherapee's thick manual.

Cheers!

Mike (PCLinuxOS DPE2 RC2)

[Quicksand]

Adding a little to what newmikey says -- I like RawTherapee, and it's free, so that's worth a shot. But I would suggest staying away from version 3.0 alpha, which is in the fairly early stages of a complete re-write. Version 2.4.1 is much more usable.

[jbinpg]

Agree with Quicksand. RT v3 series is not in what I would call a usable state yet. I do the bulk of my RAW processing with RT 2.4.1. If it had a better curves tool, I probably wouldn't need much else unless I needed layers for something fancier. Then it is off to the GIMP. My workflow currently looks like this:

SDHC card from my K20D -> card reader -> Ubuntu 9.10 (soon to be 10.04) -> Geeqie for first edits (throw away trash shots) -> good PEFs to RT 2.4.1 -> save as tif if needed for further post or resize to 33% jpg for the web.

I sometimes use LightZone (commercial) for those shots that need local edits since LZ makes this kind of work extremely easy. In that case, I would just do everything in LZ. LZ just released a new version for Windows, Mac and linux last week.

Jack

[newmikey]

Aa you said you were already using UFRaw but didn't like the results so I provided some other links. Forgot to tell you that IMHO, UFraw is capable of the highest quality output when used correctly, with the proper camera profile and color curves. I love RawTherapee but the results of UFRaw can be identical or even better.

The only problem UFRaw has is that you need to turn to some other program for sharpening - UFRaw doesn't (yet) do that.

I have settled on GMIC which I have combined with the batched version of UFRaw in a script that'll turn a whole directory of PEFs into high-quality sharpened (resized if necessary) JPEGs. It is called with: gmicraw *.PEF

#!/bin/bash
FILE="";
let "nbfiles = $#"
compteur=0
for i in "$@";do
if [ -f "$i" ];then
let "compteur +=1"
echo processing file $compteur of $nbfiles
FILE="$i"
FILE_NO_EXT=${i%.*}
ufraw-batch --conf=/usr/share/profiles/k20d.ufraw --output=- $i|gmic -.png -resize 75%,75%,1,3,5 -unsharp_octave 4,3,1.5,8,0 -gimp_mix_lab 1,0,0,1.2,0,0,1.2,0,0,0,2 -output $FILE_NO_EXT-gmic-linux.jpg,98

fi
done

[Quicksand]

Here's a link to my own raw conversion script:

https://www.pentaxforums.com/forums/post-processing-printing-software-darkroo...rocessing.html

. . . it uses dcraw for the basic conversion, then some imagemagick operations on the 16-bit TIF to sass up the colors, do some sharpening, etc.

I'll have to take a look at your GMIC approach to sharpening, newmikey. I have peered at the documentation before (in connection with chroma noise removal) but found the sheer range of operations and options to be, well, rather off-putting.

But you have given me a place to start, so thanks!

[newmikey]

Here's a link to my own raw conversion script:

https://www.pentaxforums.com/forums/post-processing-printing-software-darkroo...rocessing.html

. . . it uses dcraw for the basic conversion, then some imagemagick operations on the 16-bit TIF to sass up the colors, do some sharpening, etc.

I'll have to take a look at your GMIC approach to sharpening, newmikey. I have peered at the documentation before (in connection with chroma noise removal) but found the sheer range of operations and options to be, well, rather off-putting.

But you have given me a place to start, so thanks!

And you have given me a place to continue. I just love the idea of ISO-dependent NR and sharpening, played around with it in the past but never did get past the thinking stage.

I used DCRAW as well but I found that I have more control over the outcome when using ufraw-batch with a preset file containing info on profile, curves etc.

So rather than you thanking me, it is me who should be thanking you! I'm going to see if I can "marry" the two approaches - ISO dependent but using ufraw and GMIC.

[newmikey]

Quicksand, I tried your script and it works like a charm. Problem is, I don't like the color output of straight DCRAW and it shows in the images (especially the rather lifeless greens). I am using both a K20D color profile (if I'm not mistaken it came from Bibble) and a couple of color curves that mimick Pentax's "natural", "bright" and "vivid" settings. Unless I am mistaken, there also is quite some difference in sharpening due to using DCRAW's wavelet denoising even at low ISO.

Just as an example, I'll post the same PEF here, once as the camera shot it (RAW+), once with the DCRAW based script and once with the script I am using right now which combines GMIC and UFRaw. I hope the comparison will eventually lead both of us to an improved version, OK?

The original JPEG the camera recorded:


Your DCRAW/ImageMagick conversion:


My UFRaw/GMIC conversion:

[Quicksand]

Interesting comparison -- thanks for doing it! Is that your house in Amsterdam? It looks an awful lot like one I visited here in the U.S. a while back.

I spent a long time tweaking saturation and contrast parameters in my script, trying to get close to a reasonable set of in-camera JPG settings I had previously settled on. So a part of the difference is definitely subjective and based on my preferences.

But you're absolutely right that my greens have considerably less "pop." The blue sky seems to have similar saturation overall, but I think mine has a little more red or violet in it, pushing the blue toward grayish.

So I wonder whether a slight tint adjustment would bring them into closer alignment. Removing some violet from the green grass would definitely make it greener. I'll check it out.

Incidentally, my initial forays into GMIC for noise reduction were inspired by this blog post:

G’MIC, next-gen GREYCstoration Linux Photography

Unfortunately, I never got anywhere with it, as I mentioned before. It's still in the back of my mind. That flavor of denoising, combined with ISO-sensitive parameters, is what I wanted to achieve.

[newmikey]

Unfortunately, I never got anywhere with it, as I mentioned before. It's still in the back of my mind. That flavor of denoising, combined with ISO-sensitive parameters, is what I wanted to achieve.

That's become a lot easier now due to the command-scripting nature of GMIC. All that's needed is a "smooth 25" or "smooth 100" in the GMIC commandline and Bob's your uncle.

PS: If you enlarge the image, you can just see me walking my dog on the back lawn! I'm thinking of hiring a gardner, you can see I didn't mow the lawn for some time now. The wife is going ballistic about it

[newmikey]

Thought I'd come back to this to show some progress. I am getting close to the standard K20D colore while extracting just a tiny little bit of extra detail from the PEF (but boy, is it hard work: the K20D jpegs are nothing to sneeze at!).

The biggest advantage is the extreme level of control this now gives me. See my post on FLICKR.

The idea of doing some ISO-dependent variable setting was brilliant, Quicksand! Take a bow cause that got me started. I also made the return from UFRaw to the more basic dcraw as it seems a more straightforward way to work.

dcraw -w -v -H 5 -p "/usr/share/profiles/PENTAX_K20D.icc" -4 -c "$rawname"| convert ppm:- -verbose -modulate 125,130,102 -sigmoidal-contrast 2x35% -depth 16 png:- | gmic -.png -div 256 $greycexec -gimp_mix_lab 1.03,0,0,1.2,0,0,1.2,0,0,0,2 $octaveexec -c 0,255 -type uchar -output "$jpegname",97

The variables $octaveexec and $greycexec are set depending on the ISO rating of the image as per below details:

$greycexec= -smooth(0 0 5 10 20 40 80) for ISO 100, 200, 400, 800, 1600 and 3200 respectively
$octaveexec= -unsharp_octave 4,3,$octave1,$octave2,2 where
$octave1(strength)= 3 3 3 3 2 2 1 1 for the ISO values mentioned
$octave2(threshold)= 0 0 0 1 1 4 8 8

$rawname contains the filename of the raw file and $jpegname contains the filename with postfix "-batch" and jpg extension.

[jbinpg]

Nice work, Mike. Scripts are great for banging out images quickly. But one can easily make profiles in programs such as RawTherapee which preserves settings for various ISOs, resizing, etc., as well. You just need to pick the appropriate profile and away you go. I prefer to see my image on screen through the process. And the biggest problem with scripts is that if you don't do any weeding out of trash images before running the script, then you end up with trash on the output as well.

Jack

[georgis]

dcraw -w -v -H 5 -p "/usr/share/profiles/PENTAX_K20D.icc" -4 -c "$rawname"| convert ppm:- -verbose -modulate 125,130,102 -sigmoidal-contrast 2x35% -depth 16 png:- | gmic -.png -div 256 $greycexec -gimp_mix_lab 1.03,0,0,1.2,0,0,1.2,0,0,0,2 $octaveexec -c 0,255 -type uchar -output "$jpegname",97

ufraw-batch --conf=/usr/share/profiles/k20d.ufraw --output=- $i|gmic -.png -resize 75%,75%,1,3,5 -unsharp_octave 4,3,1.5,8,0 -gimp_mix_lab 1,0,0,1.2,0,0,1.2,0,0,0,2 -output $FILE_NO_EXT-gmic-linux.jpg,98

Hi,

I was wondering where to get those K20D profiles (in bold above)? Do you come up with those yourself? Thanks!

[newmikey]

Hi,

I was wondering where to get those K20D profiles (in bold above)? Do you come up with those yourself? Thanks!

Just back from vacation so my apologies for the late reply. I seem to remember the K20D colour profile came from a tryout version of PhaseOne software. The K20D.ufraw file is just an ID file from UFRaw that I adjusted as to curves, profiles etc. and then renamed and saved for future use.

[EDIT] the K20D color profile is here http://github.com/claes/gmic-extensions/blob/master/Profiles/Camera/Standard/PENTAX_K20D.icc on the site of Claes (Extensions to G'MIC, to use for my RAW workflow).

[mmickey]

Gimp is very cool and has lots of features. You can find many tutorials on Flickr: GIMP users discussion topics.

To overcome some of the problems of gimp, I did some plugins, which help to get eg curve adjustments in 16 bit or better downsizing. MM Filters for GIMP - mm-log

greets mike