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Dave's Luminosity Selection

Disciplines > Photography > Affinity Photo > Resources > Dave's Luminosity Selection

Download | Discussion | Smart'n'Simple Luminosity Selection | Smart Luminosity Selection | Smart'n'Manual Luminosity Selection | Full Luminosity Selection | Parabolic Darks Selection | Parabolic Lights Selection | Parabolic Midtones Selection | See Also

Download

Click here to download the latest 'Dave's Luminosity Selection' macro set.

To insert this into your library, simply click on the 3-line 'hamburger' on the top right of the library panel, click on 'Import Macros...' and point it at the downloaded file. Then click on the layer for which you want a model and click once on the appropriate macro in the 'Dave's Luminosity Selection' library group category.

Discussion

The macros in this category all provide means of selecting pixels, based on luminosity.

Overall, they work by first duplicating the visible image and then adding a Procedural Texture control to these, which allows slider and numeric controls to be added.

To use the macros, it is a good idea to first turn off underlying layers so you can see the selection being made. Then add further controls to the selection layer or convert it to such as a selection or mask for continued usage. Just using the selection layer as is allows for dynamic, non-destructive adjustments, but does pay the price of an additional pixel layer.

The Procedural Texture code for these are fairly complex and hence is not discussed here.

Version 2 changes

This macro set has been significantly revised as Version 2, making these similar to the Saturation Selection and Selection macro set. Changes from Version 1 include:

• Removing the Mono Stretch, Convert to Mask and Spare Channel, and Convert to Selection macros.

  • This was done to make them independently available for other selection macros.

  • They can now be found in Dave's Selection-Masker macros.

• Addition of 'Mono Protect' section in the control.

  • This is available also in Hue Selection and seems a useful way to enable a useful output when other controls are turned up high.

Smart'n'Simple Luminosity Selection

Description

This is based on the Smart Luminosity Selection macro but offers fewer controls as is intended for less demanding use or where the further controls are not used. Being simpler, it also uses less code and so may run faster, especially on slower computers.

Controls

Luminosity is calculated as a value between 0 and 1, and the controls offer ways to set which pixels are selected, including those which are fully selected and those which are partially selected. Partial selection give a way to feather the edges of the selection such that the selected area is less visible to the human eye.

• Middle: The central value of the selected area.

• Width: The width of area which is fully selected (opaque).

• Feathering: The width of the area outside the fully selected ('Width') area, in which pixels are increasingly transparent.

Discussion

This is still a 'smart' macro in the intuitive nature of the controls it offers. It may well be sufficient for many usages.

A simple way to use it is to first turn off the bottom (original) layer, turn Width and Feathering down low, then scan the Middle up and down to see what this shows. Then position the Middle control in the middle of the luminosity zone you want to select. Then expand the Width to select the full desired area and Feathering to soften it overall.

Then turn on the underlying layers and add further adjustments to the selection layer.

Smart Luminosity Selection

Description

This is based on the Full Luminosity Selection macro, but instead of manual control of the a, b, c and d points, these values are calculated from a more intuitive set of controls as below.

Controls

• Middle: The central value of the selected area.

• Width: The width of area which is fully selected (opaque).

• Feathering: The width of the area outside the fully selected ('Width') area, in which pixels are increasingly transparent.

• Feathering calculation: Feather: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• Selection Invert: 0=No; 1=Yes

  • 0: Normal

  • 1: Invert (select everything that is not selected in Normal condition)

• Mono Protect: Selects near-monochrome (and increasingly non-so) to exclude from the selection.

  • Note: Full monochrome happens where R, G and B are all of equal value. Moving the slider right allows for increasing max-min range within R, G and B differences.

• MP Feathering: Feathering from the maximum Mono Protect value back to full Monochrome.

• MP Feathering calculation: MP Fea: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• MP Mono calculation: Cal: 0=All; 1=Gy; 2=Wt; 3=Bk

  • 0=All: Selects most pixels based on simple 'max-min' algorithm.

  • 1=Gy (default): Selects more greys, based on HSL hue algorithm, avoiding selection of whites/tints and blacks/shades.

  • 1=Wt: Selects greys and whites/tints, based on '(max-min)/max' algorithm.

  • 2=Bk: Selects greys and blacks/shades, based on '(max-min)/(1-min)' algorithm.

• MP Invert: 0=No; 1=Yes

  • 0: Normal selection

  • 1: Invert (select everything that is not selected in Normal condition)

Discussion

In addition to notes from the Smart'n'Simple Luminosity Selection...

The simplest way of using the controls is to try them out. Make a basic selection then try varying the switches to different values.

Note that switch values are clamped to their range, so for example a value of -1 will be taken as 0 and a value of 3 will be taken as 2 (if this is the maximum).

Smart'n'Manual Luminosity Selection

Description

This is based on the Full Luminosity Selection macro, but instead of manual control of the a, b, c and d points, these values are calculated from a more intuitive set of controls as below.

Controls

• Middle: The central value of the selected area.

• Width: The width of area which is fully selected (opaque).

• Feathering: The width of the area outside the fully selected ('Width') area, in which pixels are increasingly transparent.

• Feathering calculation: Feather: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• Lumin: Red Weight (0..100)

  • Value 0 to 100% which will be used in the luminosity calculation (red-weight*R+green-weight*G+blue-weight*B).

  • Note: Weights are normalised so they sum to 100.

  • Default: 30%.

• Lumin: Green Weight (0..100)

  • Value 0 to 100% which will be used in the luminosity calculation (red-weight*R+green-weight*G+blue-weight*B).

  • Note: Weights are normalised so they sum to 100.

  • Default: 59%.

• Lumin: Blue Weight (0..100)

  • Value 0 to 100% which will be used in the luminosity calculation (red-weight*R+green-weight*G+blue-weight*B).

  • Note: Weights are normalised so they sum to 100.

  • Default: 11%.

• Invert: 0=No; 1=Yes

  • 0: Normal

  • 1: Invert (select everything that is not selected in Normal condition)

• Mono Protect: Selects near-monochrome (and increasingly non-so) to exclude from the selection.

  • Note: Full monochrome happens where R, G and B are all of equal value. Moving the slider right allows for increasing max-min range within R, G and B differences.

• MP Feathering: Feathering from the maximum Mono Protect value back to full Monochrome.

• MP Feathering calculation: MP Fea: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• MP Mono calculation: Cal: 0=All; 1=Gy; 2=Wt; 3=Bk

  • 0=All: Selects most pixels based on simple 'max-min' algorithm.

  • 1=Gy (default): Selects more greys, based on HSL hue algorithm, avoiding selection of whites/tints and blacks/shades.

  • 1=Wt: Selects greys and whites/tints, based on '(max-min)/max' algorithm.

  • 2=Bk: Selects greys and blacks/shades, based on '(max-min)/(1-min)' algorithm.

• MP Invert: 0=No; 1=Yes

  • 0: Normal selection

  • 1: Invert (select everything that is not selected in Normal condition)

Discussion

In addition to notes from the Smart'n'Simple Luminosity Selection...

The simplest way of using the controls is to try them out. Make a basic selection then try varying the switches to different values.

Note that switch values are clamped to their range, so for example a value of -1 will be taken as 0 and a value of 3 will be taken as 2 (if this is the maximum).

Full Luminosity Selection

Description

Similar to Smart Luminosity Selection, but with Middle, Width and Feather replaced with four points, sometimes simply described as a, b, c and d.

Controls

• Darker Zero (a): Below this luminosity value, nothing is selected. Note that 'Mono' indicates this is the less saturated side of the selection.

• Darker Full (b): Between Mono Zero and Mono Full, selection fades from none to full selection.

• Lighter Full (c): Pixels are fully selected for luminosity values between Mono Full and Colour Full.

• Lighter Zero (d): Pixels are increasingly more transparent between Colour Full and Colour Zero. Above Colour Zero, no pixels are selected.

• Luminosity calculation: 0=Wghtd; 1=Avg

  • 0=Wghtd: Calculated as 30% Red + 59% Green + 11% Blue

    • This is how Affinity calculates it in a number of different adjustments.

    • It adjusts for perceptual difference in luminosity, for example where Blue looks darker and Yellow looks lighter.

  • 1=Avg: Calculated as 33% Red + 33% Green + 33% Blue: This is a logical calculate but is not perceptual.

• Feathering calculation: Feather: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• Invert: 0=No; 1=Yes

  • 0: Normal

  • 1: Invert (select everything that is not selected in Normal condition)

• Mono Protect: Selects near-monochrome (and increasingly non-so) to exclude from the selection.

  • Note: Full monochrome happens where R, G and B are all of equal value. Moving the slider right allows for increasing max-min range within R, G and B differences.

• MP Feathering: Feathering from the maximum Mono Protect value back to full Monochrome.

• MP Feathering calculation: MP Fea: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• MP Mono calculation: Cal: 0=All; 1=Gy; 2=Wt; 3=Bk

  • 0=All: Selects most pixels based on simple 'max-min' algorithm.

  • 1=Gy (default): Selects more greys, based on HSL hue algorithm, avoiding selection of whites/tints and blacks/shades.

  • 1=Wt: Selects greys and whites/tints, based on '(max-min)/max' algorithm.

  • 2=Bk: Selects greys and blacks/shades, based on '(max-min)/(1-min)' algorithm.

• MP Invert: 0=No; 1=Yes

  • 0: Normal selection

  • 1: Invert (select everything that is not selected in Normal condition)

Discussion

This control lets you set different fade gradients for the lower and upper parts of the selection. The price of this is that it is more work to set up (which is why the Smart Luminosity Selection macro was written).

In making a selection, keep the a, b, c and d points in sequential order. In other words, keep a lower than b, which is lower than c and this lower than d.

The switch controls are the same as those in Smart Luminosity Selection.

Parabolic Darks Selection

Description

Enables selection of luminosity range from full darks, stretching out to lighter luminosity, using a partial parabolic curve (that may look like an exponential curve). The initial condition is like Blend Ranges with the right node pull to the bottom so a straight line from high Dark to low Light is used.

This shaping is similar to that used by other methods, though they use fixed curves with names such as 'Darks 3' and 'Lights 2'.

Controls

• Darks: Sliding left selects a shorter range (but still full black), with a convex curve. Sliding right selects a longer range towards Lights.
• Hard Width: Slides the curve right, so an increasingly wider range reaching out from black is fully selected.
• Bias: 0=Darks, 1=Lights (default 0). Selects curve family that is biased more towards darks or lights.
• Luminance: 0=Wghtd, 1=Avg

  • 0=Wghtd: Calculated as 30% Red + 59% Green + 11% Blue

    • This is how Affinity calculates it in a number of different adjustments.

    • It adjusts for perceptual difference in luminosity, for example where Blue looks darker and Yellow looks lighter.

  • 1=Avg: Calculated as 33% Red + 33% Green + 33% Blue: This is a logical calculate but is not perceptual.

• Invert: 0=No; 1=Yes

  • 0: Normal

  • 1: Invert (select everything that is not selected in Normal condition)

• Mono Protect: Selects near-monochrome (and increasingly non-so) to exclude from the selection.

  • Note: Full monochrome happens where R, G and B are all of equal value. Moving the slider right allows for increasing max-min range within R, G and B differences.

• MP Feathering: Feathering from the maximum Mono Protect value back to full Monochrome.

• MP Feathering calculation: MP Fea: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• MP Mono calculation: Cal: 0=All; 1=Gy; 2=Wt; 3=Bk

  • 0=All: Selects most pixels based on simple 'max-min' algorithm.

  • 1=Gy (default): Selects more greys, based on HSL hue algorithm, avoiding selection of whites/tints and blacks/shades.

  • 1=Wt: Selects greys and whites/tints, based on '(max-min)/max' algorithm.

  • 2=Bk: Selects greys and blacks/shades, based on '(max-min)/(1-min)' algorithm.

• MP Invert: 0=No; 1=Yes

  • 0: Normal selection

  • 1: Invert (select everything that is not selected in Normal condition)

Parabolic Lights Selection

Description

Enables selection of luminosity range from full lights, stretching back to darker luminosity, using a partial parabolic curve (that may look like an exponential curve). The initial condition is like Blend Ranges with the left node pull to the bottom so a straight line from high Light to low Dark is used.

This shaping is similar to that used by other methods, though they use fixed curves with names such as 'Darks 3' and 'Lights 2'.

Controls

• Lights: Sliding left selects a shorter range (but still full white), with a convex curve. Sliding right selects a longer range towards black.
• Hard Width: Slides the curve left, so an increasingly wider range reaching out from white is fully selected.
• Bias: 0=Darks, 1=Lights (default 1). Selects curve family that is biased more towards darks or lights.
• Luminance: 0=Wghtd, 1=Avg

  • 0=Wghtd: Calculated as 30% Red + 59% Green + 11% Blue

    • This is how Affinity calculates it in a number of different adjustments.

    • It adjusts for perceptual difference in luminosity, for example where Blue looks darker and Yellow looks lighter.

  • 1=Avg: Calculated as 33% Red + 33% Green + 33% Blue: This is a logical calculate but is not perceptual.

• Invert: 0=No; 1=Yes

  • 0: Normal

  • 1: Invert (select everything that is not selected in Normal condition)

• Mono Protect: Selects near-monochrome (and increasingly non-so) to exclude from the selection.

  • Note: Full monochrome happens where R, G and B are all of equal value. Moving the slider right allows for increasing max-min range within R, G and B differences.

• MP Feathering: Feathering from the maximum Mono Protect value back to full Monochrome.

• MP Feathering calculation: MP Fea: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• MP Mono calculation: Cal: 0=All; 1=Gy; 2=Wt; 3=Bk

  • 0=All: Selects most pixels based on simple 'max-min' algorithm.

  • 1=Gy (default): Selects more greys, based on HSL hue algorithm, avoiding selection of whites/tints and blacks/shades.

  • 1=Wt: Selects greys and whites/tints, based on '(max-min)/max' algorithm.

  • 2=Bk: Selects greys and blacks/shades, based on '(max-min)/(1-min)' algorithm.

• MP Invert: 0=No; 1=Yes

  • 0: Normal selection

  • 1: Invert (select everything that is not selected in Normal condition)

Parabolic Midtones Selection

Description

Enables selection of a range of luminosity values, based on an inverted parabolic curve.

Controls

• Middle: Sets the luminance value to be fully selected. Selection falls off either side of this point.
• Soft Width: Moves the selection parabola down, so less pixels are fully selected.
• Hard Width: Moves the selection parabola upwards, so more pixels are fully selected.
• Luminance: 0=Wghtd, 1=Avg

  • 0=Wghtd: Calculated as 30% Red + 59% Green + 11% Blue

    • This is how Affinity calculates it in a number of different adjustments.

    • It adjusts for perceptual difference in luminosity, for example where Blue looks darker and Yellow looks lighter.

  • 1=Avg: Calculated as 33% Red + 33% Green + 33% Blue: This is a logical calculate but is not perceptual.

• Invert: 0=No; 1=Yes

  • 0: Normal

  • 1: Invert (select everything that is not selected in Normal condition)

• Mono Protect: Selects near-monochrome (and increasingly non-so) to exclude from the selection.

  • Note: Full monochrome happens where R, G and B are all of equal value. Moving the slider right allows for increasing max-min range within R, G and B differences.

• MP Feathering: Feathering from the maximum Mono Protect value back to full Monochrome.

• MP Feathering calculation: MP Fea: 0=Lin; 1=Exp; 2=Cos

  • 0=Lin: Linear feathering, steadily fading from edge

  • 1=Exp: Exponential sigmoid feathering, s-shaped fade

  • 2=Cos: Cosine sigmoid feathering, different s-shaped fade

• MP Mono calculation: Cal: 0=All; 1=Gy; 2=Wt; 3=Bk

  • 0=All: Selects most pixels based on simple 'max-min' algorithm.

  • 1=Gy (default): Selects more greys, based on HSL hue algorithm, avoiding selection of whites/tints and blacks/shades.

  • 1=Wt: Selects greys and whites/tints, based on '(max-min)/max' algorithm.

  • 2=Bk: Selects greys and blacks/shades, based on '(max-min)/(1-min)' algorithm.

• MP Invert: 0=No; 1=Yes

  • 0: Normal selection

  • 1: Invert (select everything that is not selected in Normal condition)

See also

If you are having problems downloading the macros, click here to download as zip file.

Dave's Zone System

Dave's Saturation Selection

Dave's Hue Selection

The Version 1 downloads are still available here or as zip file. Also here is this web page for Version 1. Version 2 downloads are here or as zip file.