Hello,
With pleasure, and thank you again for your help in compiling the Windows versions.
I believe I have introduced a true ‘pyramidal decomposition’ for frequency scales. Unlike the previous multi-scale approach, this pyramid strictly separates frequencies. This architectural change allows for the implementation of dynamic ‘Pyramidal Edge Protection,’ which, in theory, drastically reduces halos compared to previous versions.
Here are the pillars of this approach:
- Quadratic logic of the Edge Protection slider
I introduced a squared logic (base\_eps = feathering^2). Since the parameter is already the inverse of the slider value (1/p), squaring it makes the adjustment much more responsive and precise in the critical area. Where a linear slider would double the effect, this approach quadruples it, offering unprecedented finesse of control over contour sensitivity.
- The ‘Pyramid of Intensities’
The Epsilon (the detection threshold) adapts to each level:
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Extended Scale: Larger Epsilon (* 1.5). The filter is more ‘permeable’ to smooth large volumes naturally.
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Micro Scale: Smaller Epsilon (* 0.5). The filter becomes precise and refuses to smooth over sharp contours to preserve micro-details without halos.
- The ‘Protection Pyramid’ (Edge Sensitivity)
Fixed multipliers (from 1.80 for Micro to 0.80 for Extended) weight the Epsilon. This allows for much stricter control over large shapes (where halos are most visible) while remaining more flexible on fine textures so as not to amplify digital noise.
- The ‘Contrast Scale’ slider (Intelligent Blending)
This slider does not lower frequencies uniformly. It is a proportional scale factor: when increased, the ‘Extended’ layer rises faster than the “Micro” layer (crisp details). This preserves the natural balance of the photo and accentuates the modelling without giving an artificial ‘HDR’ appearance.
By combining these pyramids, you get an automatic balance: more power for
modelling and more precision on the contours to avoid halos. The user no longer has to struggle with the settings; the system ‘pre-calibrates’ the protection according to the scale.
- Practical side: My workflow
In general, I prefer to start with the overall contrast and then shape it with the CSF slider, which becomes active automatically.
Next, I like to make an initial adjustment (if necessary) with the ‘colorimetric contrast’ slider, which affects the brightness between red and blue to create separation without changing the white balance.
Next comes the pyramidal local contrast adjustment. Each slider affects a specific area of the image:
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Extended & Broad: These are your modelling tools. They affect large areas of light and shadow. For example, to give relief to a face, depth to a landscape or soften the background.
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Local: This is the ‘structure’ and reference contrast relative to the others. It reinforces the presence of the main objects.
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Fine & Micro: These are the texture sliders. They bring out the detail of fabrics, skin pores or the sharpness of a lens. A negative value can be very useful for portraits (to reduce skin imperfections).
Fine adjustment of scales (Visualisation)
The module includes visualisation buttons for each layer (the mask icon next to each slider) to check that your ‘Edge Protection’ is set correctly.
You can either adjust the main ‘Pyramidal Edge Protection’ slider until you obtain a ‘clean’ mask at the edges (to ensure there are no halos when applying contrast), or use the dedicated sliders to fine-tune the scales individually.
Depending on the mood of the photograph, you can also use the Contrast Scale (Blending) slider, which will dynamically shift all scales. A higher value will have less effect on very fine structures, which can be useful for a very noisy photo.
And for the final touch, we can balance the global or pyramidal part with the “global<>local balance” slider.
Greetings from Luberon,
Christian
PS. Translated from French (AI) Here is the French PDF.
20260216 Pixls forum.pdf (44.5 KB)
