Hi all,
having seen the post on Lightroom sliders here are some examples from PhotoNinja’s “Details” slider, which does an amazing job at bringing out detail without altering realism or colors. That’s the slider I miss most in RT. There surely is some magic under the hood, but perhaps these samples will inspire something. Or perhaps RT already has the capability of bringing out detail this way, if that’s the case please tell me how!
Producer’s info here: Photo Ninja Showcase: Detail enhnancement
Samples:
The best I could get in RawTherapee (using gentle tone-mapping, wavelets contrast and edge sharpness, as well as lab adjustments for preserving hues) still missed some details especially in the grasslands and woods (can’t post a sample because of 4 pics limit).
To me, it looks like an high-pass sharpening where a sort-of-bilateral filter is used for smoothing the initial image and extract the high-frequency component.
At least, the -50 setting seems to be close to the smoothed image, and looks like some sort of edge-preserving smoothing filter like the bilateral one.
I will experiment a bit when I’ll be able to open this post with the laptop.
Wow, retinex with a small radius (20) is impressive!
Here three samples (same image as before, not cropped but scaled): first photoninja with detail +20, then RT with tone mapping, finally RT with retinex. Notice the detail in those regions where there are small shrubs instead of big trees.
That’s exactly what I was after, but I notice three minor things:
1- Most important, Retinex produces some ugly artifacts at the edges. Here’s a 100% detail:
2- Retinex strongly lifts the deep shadows introducing strong luminance noise in those regions (bottom-left of the image). Photoninja’s detail slider just ignores those regions. Is there a retinex-shadow-protect-slider? I miss some documentation concerning the “transmission” and “gain/offset” sections of retinex. I’m able to partly recover this by increasing the wavelets’ residual image contrast, but not completely.
3- Retinex seems to miss the clouds detail - which give beautiful volume - probably because of the small radius needed for the mountain detail. Maybe photoninja uses a variable radius according to the region’s detail, and then blends the result? What can I try to improve the clouds volume?
Maybe the functions under the wavelet tab in RawTherapee can also help you with details (Edges). (edit: I now see you did try this)
I think, in PhotoNinja , it is something like gradient-sharpening (and smoothing).
There is also a gradient sharpening filter in G’MIC (for GIMP) under Details, but that filter works only positive, it doesn’t smooth. (Altough, with grain extract layer, thereafter grain merge with original, you can smooth with it, but not interactive. It is a little bit reverse engineering).
Tone mapping is what I tried first, it’s used in the 2nd image from my latest post. It doesn’t enhance enough the fine details in the shrubs, I think. But it’s true I’ve used it with 5 iterations in the Retinex tool. Is there a good way to get the artifacts away without losing sharpness?
Retinex is something entirely different, and the tone mapping slider in Retinex does not work the same way as the main Tone Mapping tool does. Retinex can enhance detail but it does other things too. If all you want is to enhance detail without lifting shadows and globally changing the light then using Retinex is probably not the way to go. The main Tone Mapping tool is the one I recommend for this purpose. Zoom to 100% and use the Edge Stopping slider as the link explains to change the scale of enhanced detail.
Any further advice is complete guesswork if you don’t share the image.
There are many ways of enhancing a certain level of detail in RawTherapee. Rather than trying to imitate some slider from some other program, explore the tools and find out their strengths for what they are in their own unique way.
and here the profile I’ve used for the 3rd image in the above post: http://tiny.cc/7co0cy
In fact I have explored most of the detail tools, and I have used some of them in the above samples, but for this particular photo retinex gives the effect I like best. But I really hoped there was something to avoid those edge artifacts!
No, those artifacts come from the Wavelets tool.
You can’t enable every single sharpening tool in RawTherapee including strong first level wavelet contrast and expect to get good results.
The image without any detail enhancement:
Wavelet > Edge Sharpness alone leads to very good results:
