Advanced Sharpen - I'm Confused

[bobsofpa]

In the newest version there is now two sets of black and white sliders in Sharpen window of Advanced Sharpen. I assume one set is for sharpen as it always has been which should be the two sliders to the far left and the other set at the far right I assume is for halo reduction.

With the above being correct, once I move them how do I tell the sharpen black/white slider from the halo black/white slider?

[tomczak]

The histogram in AS/Sharpen shows 'roughness' on its X-scale: fine features to the left, rougher edges to the right. The two double sliders below the histogram allow you to exclude either or both of finest and roughest elements of the picture from sharpening at all. Note that this work in tandem with Sharpen Radius: larger radii make make more small details being defined as smooth.

Once you decide which elements are to be sharpened at all, the Halo Reduction sliders limit the maximum overshot/undershot (i.e. halos) around sharpened elements. You can use it to selectively suppress most visible halos (often, but not always, white overshoots on major edges) and allow for optimizing sharpening where it is needed and not objectionable.

The new features of AS sharpen (i.e. dual sharpening thresholds and halo control) are nothing short of revolutionary and allow for achieving final results that were either extremely labour intensive or outright impossible previously.

I (and I'm sure others) will be more that happy to answer any questions as to the use of the new, vastly improved, AS. It's really that good.

[jsachs]

Two sets of black and white markers are displayed below the roughness histogram - the brightness of the bar under the histogram indicates to what extent parts of the image of a given roughness are sharpened - white for full sharpening, black for no sharpening. The left markers let you prevent sharpening very smooth areas to keep them smooth, the right markers let you prevent sharpening very rough areas. By reducing the sharpening of very rough areas you can cut back on oversharpening parts of the image that are already sharp (i.e. have distinct edges) and reduce halos.

The halo reduction sliders like those in the other sharpen transformations do something similar by limiting the amount by which any pixel can be lightened or darkened by sharpening.

[davidh]

Talking about Advanced Sharpen, it looks as if the second example image in the Noise Reduction section of the Advanced Sharpen white paper is wrong as it shows the Sharpen tab instead of Noise reduction tab.

I apologize for this a bit unrelated post to the original topic but this might also cause some confusion, as the Sharpen tab shows just the opposite of the description below it: "If you don’t
cover the peak with the white part of the bar....". And it is easy to overlook, at least initially, that the tab belongs to Sharpen.

David

[tomczak]

There is a new post in Tips section that may help to shed some more light on the original question of this post.

http://www.dl-c.com/board/viewtopic.php?f=5&t=1051