Generalized Hyperbolic Stretch

I know !

I think I didn’t understand what you meant, I’ll look again

jacques

What I meant was that the representation curve behaves incorrect when choosing manual or flexible curve, all with default ghs values. Setting the stretch factor slider to 0.001 solves that.

@paulmatth

I just made a “small” modification that should (I hope) solve this problem. Binaries in development

Thank you.

Jacques

That’s fast !!

@paulmatth

This is a very small and simple modification
 One oversight: the function was enabled even though it did nothing.

@jdc
Works better now. One last thing, when switching curves (manual, flexible
) the curve goes back to neutral without white points, even if the sliders are set to non-default values. Changing the stretch factor with 0,001 point shows your representation curve again.

1 Like

@paulmatth

As you know, GUI programming is not my thing at all. I don’t think I can fix this (small) problem. I send the “system” the curve type “NURBS”, and it does it.
The others selections are inactives and cause a reaction of type “Linear”, and I don’t know how to remove them from the selection. But does it matter? I think writing it in the documentation is sufficient (unless someone knows how to do it)

it’s already written in the tooltip.

Thank you again for testing.

Jacques

I think it’s important to remove options that do nothing. I understand why you’d leave it in when gui coding is not your thing but imho it can’t be left in shipped software like that. Hopefull someone can help eventually.

I hope I will find a solution today
Jacques

For the S curve GHS.

I made “my way” changes to have a coherent interface. You have the choice between “linear” and “ghs”, but in both cases, you have to forget the notion of curve as we know it.
Here it is a representation of the GHS transform with 20 points each spaced 0.05 apart (scale 0
1).
You cannot modify this curve (other than with the sliders B, D, SP, LP, HP). The system is not reversible - we cannot, from the curve, generate the corresponding values ​​of the sliders.

I also changed the tooltips a bit to better understand the images we are used to (which are rarely astronomy images)

Executables
ghs

1 Like

Works well now, Jacques.

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I’ve not had a chance to test the new changes but the above sounds perfectly reasonable. The curve as simply a visualisation of the sliders is a very useful feature.

2 Likes

I made some changes that do not affect the process or the algorithm, which should provide help with use.

The Symmetric point (SP) and Black point (linear) sliders have now a logarithmic scale making the current range of use more visible. Reminder: as all settings are very sensitive you can use the “Ctrl” key while moving the slider to have a more precise setting.

I added in the GHS curve, an estimation of the RT-spot references (even in mode Global, you have the small RT-Spot circle) : the transition between the gray areas corresponds to an estimate of the values of the 3 references of the RT-spot (saturation, luminance, hue). This can help you adjust the system especially the incidence of Symmetry Point (SP) and others sliders


I also enabled by default the “Recursive references” mode (in Selective Editing > Settings), to allow an update of the references (hue, luminance, saturation) when you change GHS settings (to enable this change in a current file, you must set to neutral, or clean the cache, or change manually this checkbox)

Executables
ghs

Jacques

Jacques,

  1. I compiled the latest version but the curve options still appear in the drop-down menu next to the label “GHS S curve” i.e. Linear, Standard, Flexible etc. These don’t actually do anything but they will create confusion.
    I agree with @nosle that options which do nothing should be hidden.

  2. The label in the second drop-down menu should be all capitals to be consistent with the curve label i.e. GHS instead of Ghs

  3. There is an “s” missing in the label “Black point & White point & Highlights”. Also, the repeated use of “&” in these labels makes them a bit cumbersome in my view. In the Transform tab and in the Exposure tab the symbol “/” is used when there is more than one function in the title (i.e. Lens/Geometry, Shadows/Highlights). If we follow that convention, the label should be “Black point/White point/Highlights”. The tool label is a bit more problematic because it would become Shadows/Highlights/Equalizer/GHS .

  4. I also noticed that the effect of the graduated filter gets stronger (in the preview) as you increase the zoom level.

@Wayne_Sutton

Thank you for testing :smiley:

I’m having trouble understanding why the GUI reacts differently - I don’t doubt for a second the behavior with “Linear”, Standard"
“Control cage” on your machines.

I tested with many images under Windows 11 Ubuntu 24.04. In all cases I only have the choice “linear” and “GHS”

Maybe it comes from the optional curve type storage file “options.lastlocalCurvesDir”. I Change this type for GHS and Selective Editing with “options.lastlocalCurvesDirghs”.

Can you tell if it does anything. For me, no difference.
If the fault persists, it will be necessary to call upon a GUI specialist and its somewhat specific implementation in Selective Editing.

I made the changes to the labels as you recommended.

For the point 4, when you speak of “graduated filter”, I suppose it is GHS? I will have a look. In the first examination, 4 to 5 points of the image identified by "Lockable color picker’ and zooming from 14% to 400%, I don’t see any major changes except for some variations in the decimals (eg 68.4
 68.6). But I will look again.

Executables
ghs

Thank you again

Jacques

1 Like

@Wayne_Sutton

I just made another change in GUI, not sure if this is useful :wink:

New executables running

Jacques

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Bonjour @jdc, here are three screen shots taken at 16%, 33% and 100% zoom with the graduated filter strength set to 1.0

Screenshot from 2024-10-10 10-08-56
Screenshot from 2024-10-10 10-10-21
Screenshot from 2024-10-10 10-11-43

As far as the menu is concerned I’m referring to the first arrow after the label “GHS S Curve”. If you click on this arrow you get the drop down menu for the curve type e.g.

image

Bonne journée,
Wayne

@Wayne_Sutton

I think I found a workaround, more of a hack, but it seems to work.

I didn’t see the problem with this double choice proposed. Thanks.

But, if someone has a better solution, I’m not at all a specialist in code and GUI, of course he can modify my code.

Executables
ghs

I will look for the zoom problem :wink:

Jacques

@Wayne_Sutton

I looked at the problem with RGB values ​​when zooming. I think it was a problem with measuring the equivalent luminance according to the working profile.

It should now work much better (I hope), although there may be slight differences, due to calculations and ‘Lockable color picker’ precision.

But if you want I can add an option to the menu “RGB, Luminance, saturation, hue” to have on the one hand the “normalized” and “non-normalized” RGB values ​​RGB: RGB human vision, standard RGB, Luminance, saturation, hue" (easy to do)

running executables
ghs

Thank you

Jacques