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Marcel Maes
Member
Username: Marcel_maes

Post Number: 13
Registered: 08-2006
Posted on Tuesday, September 26, 2006 - 07:41 pm:   Edit Post Delete Post

In thread http://www.dl-c.com/discus/messages/2/9822.html?1158019455 I wrote to be convinced that PWP has every tool needed to enhance a photo, even a dull-looking native RAW-file.
Substractive filtering an image with it self may have some disadvantages as some of you stated.

Looked for another method.
The Transformation > Grey > Brightness curve still didn't give good results with RAW files.
Good (usable) masks are also hard to make in low-contrast pictures.

I tried Transformation > Color > Curves.
After one or two trails I was pretty sure that the colorcurves can "do the job" and with that assumption and some patience, I got very good results with every picture.
The results resemble very much the substractive filering method.
The pleasant difference is that a good ColorCurve does not oversaturate colors that already were saturated in the original. (see example, sorry for the very poor quality, but it the already small picture still had to be compressed twice)

example

File > RAW settings:
- Camera make and model: Default
- Gamma: 2,2
- Contrast: No expansion
- Color profile: Canon Digital Rebel XT
- White point: Camera WP
- Color space: sRGB
- Preferred interpolation: AHD


Right after the RAW files is loaded
Transformation > Color > Curves
- Choose color space HSL.
- Choose L (ightness) first and apply a S-curve (start with a 4 point curve, only one extra point seldom works fine)
- Then choose S and also add two control-points to make an S-curve here too.
- You maybe have to switch between S and L to fine-tune
- Be carefull not to add too much extra noise in the darker areas

Now you should have a pretty good picture already.
Further editing should include sharpening of course.
Some pictures also may benifit by the automatic Transformation > Color > Balance option before applying Color Curves

After first being dissappointed, I'm now in fact glad that the PWP-programmers did NOT enhance the RAW files as many RAW editors do.
We have everything in our own hands now.
Compliments for this philosophy guys!

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den
Member
Username: Den

Post Number: 69
Registered: 03-2006
Posted on Wednesday, September 27, 2006 - 09:19 am:   Edit Post Delete Post

MarcelM....

I too have a Canon Rebel XT but due to an 'ancient' computer system and OS generally work with the camera's highest jpg quality and pixel size download files where the parameters for contrast, sharpness, saturation, and tone are either 0,0,0,0 or -1,-1,-1,0....

Would you mind if I experimented with a file that you provide?

I would like to explore your findings particularly the ColorCurves transform in HSL color space... I generally will use the HSV color space except for enhancing an image's 40->100% tone range [skies/clouds]...

Also I would like to explore the possibility of using 'Composite-ADD' the image with itself [this seems to provide a brighter and more contrasted image than Subtractive Filter-ing an image with itself] and the Levels&Color transforms...

Requested working image criteria...
1. Resize a RAW converted working [or tiff] file to 800x1200 pixels using PWP's Resize tranform, default bi-cubic settings...
2. File Save as jpg compressed at 100% quality
3. Advise an URL for download or email to:
"birch_bay at hotmail . com"

With your permission, I would make my explorations available to others but if not at least to you....

Thank you for your consideration of this request.
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Marcel Maes
Member
Username: Marcel_maes

Post Number: 14
Registered: 08-2006
Posted on Wednesday, September 27, 2006 - 06:41 pm:   Edit Post Delete Post

Den,

What struck me most when working with the Color Curves for the first time, were the fine details that came out, even before having sharpened the picture.
In a 800*1200 image those fine details may disappear.
But anyway, I don't mind sending you a picture (or even more) to experiment with.
Check your mailbox.

Marcel
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Keith Ross-Jones
Member
Username: Keithrj

Post Number: 27
Registered: 03-2006
Posted on Wednesday, September 27, 2006 - 08:48 pm:   Edit Post Delete Post

One tool that often gets overlooked is Transformations -> Gray -> Levels and Color. Here you can adjust Color Balance, Saturation (HSL or HSV), Midtones and Dynamic Range. For getting a quick starting point for more detailed work I find this tool very quick and easy to use.

Not sure why it is under the Gray menu as I think it should be in the Color menu.
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Jonathan Sachs
Member
Username: Jsachs

Post Number: 556
Registered: 08-2002
Posted on Thursday, September 28, 2006 - 08:11 am:   Edit Post Delete Post

It's under Gray because all the Color items are greyed out for B&W images, and Levels and Color still works on B&W images albeit with the color controls disabled.
Jonathan Sachs
Digital Light & Color
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Bruce Bodine
Member
Username: Bbodine9

Post Number: 28
Registered: 09-2005
Posted on Thursday, September 28, 2006 - 08:45 am:   Edit Post Delete Post

Marcel,

Can you please explain or post what you mean by a 4 point curve and 2 point curve ? Thank you !
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den
Member
Username: Den

Post Number: 70
Registered: 03-2006
Posted on Thursday, September 28, 2006 - 11:06 am:   Edit Post Delete Post

Marcel.. recvd your image and curves... thanks. The reduced sizing is sufficient to experiment with and is easier for data transfers and my slow computer processing time... besides the lower resolution discourages 'pirates' but is sufficient to show methodoly on a monitor...


KeithRJ... I too use the L&C transform for preliminary imaging enhancement concepts... but sometimes wish....

OT to Jonathan/Kiril... re Levels and Color transform:
What is the possibility of adding a +/- Gamma slider that one could mouse shift-click adjust similar to the Midtone slider to the tranform.
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Marcel Maes
Member
Username: Marcel_maes

Post Number: 15
Registered: 08-2006
Posted on Thursday, September 28, 2006 - 03:28 pm:   Edit Post Delete Post

Hi Bruce,

Oops, my English isn't that good as I thought, but I'm sure when you read this, you'll go "oh that"

An initial curve in the color- and grey- transformations has only 2 points that go through 0,0 and 100,100 so de facto it's a straight line.
To get a 4 point curve as I meant it, add two additional controlpoints on the line (Shift-Click), then drag the points to get a curve.

sorry again and Happy Dragging ;-)

Marcel
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Marcel Maes
Member
Username: Marcel_maes

Post Number: 16
Registered: 08-2006
Posted on Thursday, September 28, 2006 - 04:36 pm:   Edit Post Delete Post

Keith,

I too use the Levels and Color transformation very often, but mostly to give an already fairly good picture the extra "thad".
For the very dull looking initial RAW pictures - and I now find that this no flaw of PWP - it just didn't give the vibrant results I'm used to get from Canon's DPP or RAW shooter.
With the Levels and Color Transformation and the Transformation > Grey > Brightness curve they still looked as if there was a grey filter over the picture.

I took me some time to figure out what makes the difference then.
It was not the "ends": pure white and deep-black were already there in the RAW picture.
But it seemed to me (by visual comparison) that the lightness- and color-contrast in the MIDtones made the difference and that can only be done with curves.
But for a quick start, indeed, the Levels and Color does a fine job.
By the way, there is also a "full range" option in the Color Balance dialog, which can be helpfull too.
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den
Member
Username: Den

Post Number: 71
Registered: 03-2006
Posted on Thursday, September 28, 2006 - 10:10 pm:   Edit Post Delete Post

Marcel has provided an image and granted permission for posting that illustrates his Color Curves transform HSL curves approach.

A image blending approach is presented as well.

Link: http://www.ncplus.net/~birchbay/tutorials/MMs_IMG_0025/index.htm

example

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den
Member
Username: Den

Post Number: 75
Registered: 03-2006
Posted on Thursday, October 05, 2006 - 02:35 pm:   Edit Post Delete Post

In a previous post in this thread, I alluded to a 'gamma' adjustment slider be added to the Levels and Colors transform. ElieD in another thread clarified for me some definitions re 'gamma' and what I was really asking for: that was... to tie saturation/hue to tone changes as is done in the Gamma transform. This cannot be simply done as the Levels and Color transform only functions in the HSV and HSL color spaces where saturation/hue are independent of tone... so rightfully so, the suggestion should/is withdrawn.

I was/am not overly happy with the 'final preference' Version3 image for MarcelM's Paris image whose workflow is linked in my post above. The multi-stepped blended image approach in the HSL/HSV color spaces results in a rather heavy-handed gothic ambience image.... and also there needed to be a simpler approach the would still result in a photo realistic image...

That approach is described here: http://www.dl-c.com/cgi-bin/discus/show.cgi?tpc=2&post=18492#POST18492

An image resulting from a single transformation with mask is on the left with Version3 on the right....

example2

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