Digital Light & Color

See the latest version of Sharpen.pdf for a detailed explanation of bilateral sharpening.

I second Jonathan’s referenced white paper… a must read for BilateralSharpen transform understanding.

Creative Sharpening using Mid-tone BilateralSharpen LCE/Edge Sharpening:
(1) Open or click on a ‘starting image’ [3474x2413 pixel, 48-bit color, 46MB image].
(2) Open the Mask Tool-BrightnessCurve. Form and ‘lower-left’ Apply, Add a Smooth curve = [0,0], [10,0], [30,100], [70,100], [90,0], [100,0]. Leave the Mask Tool ‘active’.
(3) Click on the ‘starting image’. Open Sharpen/BilateralSharpen setting: the Blur Radius = 20; Blur Threshold = 100; Sharpen Factor = 1.25; Sharpen Threshold = 0; and Mask white Amount = 65 to 100 [set to preference while monitoring Preview]. The Preview ‘Mean Image’ will take approximately two minutes with a dual core processer. See Comment (3) below.
(4) Click Apply.
(5) Click on Sharpen/BilateralSharpen setting: Input = ‘the resulting (4) image’; Blur Radius = 5; Blur Threshold = 39.22; Sharpen Factor = 1.50; Sharpen Threshold = 7.84; and Mask white Amount = 35 to 65 [set to preference while monitoring Preview]. See Comment (3) below.
(6) Click OK, creating the mid-tone LCE/EdgeSharpen-ed image.

Comments:
(1) The 'Mean Image' compute time can be shorten somewhat if one: (1) extracts the H, S, and V channels; (2) performs the mid-tone BilateralSharpen LCE/EdgeSharpening on the V channel; and (3) then CombineChannels the processed V channel with the original H and S channels... although this will not increase the color LCE/Edge contrasts, i.e., "luminance only" sharpening.
(2) The mid-tone mask, Smooth curve = [0,0], [10,0], [30,100], [70,100], [90,0], [100,0], prevents loss of detail due to posterizing and sharpening noise in the ‘starting image’s’ 0 to 10% shadows and the 90 to 100% highlights.
(3) Uncheck the Auto Preview box so that the Blur Radius, Blur Threshold, Sharpen Factor, and Sharpen Threshold settings can all be made. Then click on the Preview button to start the ‘Mean Image’ computation for the Preview image.

Comments -- continued:
(4) I use BilateralSharpen often and find it useful to have Default Preview set to 'Manual' in File/Preferences so that the transform's Blur Radius and Blur Threshold can be set without starting the 'Mean Image' computation until clicking on the Preview button or checking the Auto box.
(5) As the suggested EdgeSharpening settings are the default BilateralSharpen settings, it might be more convenient for Step(4) to click OK and for Step(5) to click on the resulting Step(4) image and re-open Sharpen/BilateralSharpen transform.
(6) Also, one could generate a Workflow wfl file with two BilateralSharpen widgets with the suggested LCE/EdgeSharpening settings, and then manually Composite-Blend the 'starting image' using the mid-tone Mask with the resulting wfl image version as the Overlay... to limit LCE/EdgeSharpening to the mid-tones.
(7) My starting files are usually from a Canon 350D camera so they may be generally softer than other camera files... hence, the suggested sharpening settings a bit strong.

Comments -- continued:
(8) Capture Sharpening to preferences while monitoring Preview is normally done with Preview set to 1:1 so as to not make adjustments to preferences that include anti-liaising effects at other viewing ratios... leaving sharpening that considers anti-liaising effects when necessary to Output Sharpening.

Also, if there is interest, an illustration of mid-tone BilateralSharpen LCE & EdgeSharpening using the suggested workflow sequences is here: http://www.ncplus.net/~birchbay/tutoria ... geshrp.htm. The image itself is not too special... I was just experimenting with taking photos with dark gray skies as the fall/winter skies will soon be the norm in my part of the world.

Den,

I've used your two stage Creative Sharpening process on a number of photos - mostly on portraits - and find the end result most pleasing. Crispness without harshness. (Sometimes in conjunction with your spec removal/add noise tips for dealing with 'shiny' highlights from flash photography)
The workflow to handle the two stage bi-lateral sharpening steps, followed by composite with the mid tone mask is reasonably convenient, and has the benefit that the workflow 'remembers' the recommended bi-lateral sharpening settings. A further aid to my failing memory is to load the previously saved mid tone curve for the mask brightness curve. I do adjust the curve if that seems appropriate for a particular image.

Good stuff! I commend it to others.

Mike.

Mike,

You talk about two stage.

Is this different to the Three Stage that Den has been talking about in this thread.

I am confused.

Tony

Tony,

You have every right to feel confused - it's my sloppy use of terminology. I was referring to the two bilateral sharpening steps. The whole process consists of more that those two steps.
Apologies,

Mike.

Tony,

My last post was very late at night, Sydney time, and a bit too brief for clarity.

As I understand things, the Three Stage Sharpening title of this thread refers to three stages as follows:

1. Capturn sharpening
2. Creative sharpening
3. Output sharpening

(Please refer to the first two posts in the thread for more detail)

The post of mine that confused you referred only to the Creative sharpening step.
Hope that this makes up for the lack of clarity in my original (and follow up) post.

Mike.