...July 3, 2017...

... High Pass Sharpening with light/dark Halo control ...

For the nature/landscape photography I prefer, I like to use multiple and sequential High Pass sharpening at various blur radius to increase contrasts for small, medium, and large image area details but miss the light/dark Halo controls that other PWP7 sharpening transforms have.

At present I use a sequential PWP7 “snippet” *.wfl but cannot incorporate a Halo control until after the *.wfl process using Composite-Blend with an original image and the workflow output image and a Halo control mask.

More detail as to what I do currently:
  High Pass sharpening, single or multiple passes used for:
      1)   small detail [adjustable 1 to 5 Blur radius, perhaps 3],
      2)   medium detail [adjustable 5 to 15 blur radius, perhaps 10], and
      3)   local contrast enhancement [adjustable 15 or greater blur radius, perhaps 40]
At present, preferred sequence for multiple passes is 2), 1), and finally 3).   Sometimes 2), then 1) can be serially performed as describe in step ...1) and its Option2 below.

Proposed: High Pass sharpening with light/dark Halo control; 0 to 100 Threshold; 0 to 256 Blur Radius; Composite Soft Light or Hard Light blending; and optional Luminance channel High Pass with Soft or Hard Light blending to avoid color changes.

A Single-Pass Manual work flow steps using PWP7 where Img0 = starting image for medium and included optional small detail sharpening:

...1)   Click on Img0 and open the Blur-High Pass transform creating “Img1-RGBcolor” with preferred settings.   Option1: Extract Img0’s Luminance channel and create a preferred Blur-High Pass image version, “Img1-Luminance”.   Perhaps for medium detail: Amount = 100; Threshold = 100; and Radius = 10.

Option2: add-in Small Detail edge contrasts by clicking on either the "Img1-RGBcolor" or Img1-Luminance" High Pass image version and open Sharpen-Unsharp Mask with initial settings: Amount = 100; Light Halo = 3.5; Dark Halo = 87.5; Radius = 2; and Threshold = 3... ...increase the Threshold setting if interpolation artifacts appear especially in large low contrast image areas like sky/clouds.

. . .a HighPass Medium-Small Detail Snippet *.wfl;   just add an Output widget. . .

...2)   Click on either Img1 versions and open/lower-left Apply Add a Mask Tool-Brightness stair step Curve [0,0] [50,0] [50,100] [100,100]… …click OK or leave mask ‘active’.   Mask white = light Halo amount control and Mask black = dark Halo amount control.

Hint: OPT-Load a previously saved curve file whose text version is:

Curve 1.0
npts 2
style step
histexpand 0
point 0 0 0
point 1 128 255
end

...3)   Click on Img0 and open Composite-Hard Light or Soft Light where: Input = Img0; Overlay = either Img1 versions, Overlay Amount Mask = the resulting ...2) mask.   Perhaps Input Amount = 50; Overlay Mask white Amount = 20; Overlay Mask black Amount = 100; and Operation = Hard Light, often preferring Soft Light depending upon desired ambience.

...4)   Adjust the Composite transform settings to preference while monitoring an updating Preview.   Click Apply or OK.

. . .step ...4) workspace view with an 'active' mask applied to Img1, the Overlay image. . .

...5)   Click on the resulting ...4) image and repeat ...1) through ...4), if preferred, selecting a different High Pass blur radius in step ...1).