Three Stage Sharpening

[Martinc]

The posting of this little article on sharpening http://photo.net/digital-darkroom-forum/00UZQR appeared on the front page of photo.net for all the wrong reasons. There is also a url a bit further on in the item that allows you to download the tutorial also. Aside from the debate about posting etiquette - bit of a storm in a tea cup - has anyone created a workflow that would effectively replicate the approach here. I can imagine a similar three stage approach using advanced sharpening, but what are the equivalent settings for the various PS sharpening approaches in PWPro.

I believe this sharpening approach is based on the work of Bruce Fraser so Id be interested in comments on whether this does produce a superior result also!

Tks in advance M

[den]

Reference:
B Fraser, Out of Gamut: Thoughts on a Sharpening Workflow: http://www.creativepro.com/article/out- ... g-workflow

1 -- Capture Sharpening is applied early in the image-editing process, and just aims to restore any sharpness that was lost in the capture process.
2 -- Creative Sharpening is usually applied locally to accentuate specific features in an image-for example, we often give eyes a little extra sharpness in head shots.
3 -- Output Sharpening is applied to files that have already had capture and creative sharpening applied, after they've been sized to final output resolution, and is tailored to a specific type of output process

Yes, sharpening for a specific purpose as one progresses through an image's post-processing workflow will improve the final result because at each stage specific issues are optimally addressed. This is a very large topic and PWPro has various sharpening methods that adequately do the job. AdvancedSharpen should not necessarilly your only consideration as not all images are the same nor will your final image version goals be the same... landscapes/nature images need/have different considerations then perhaps studio portraits, for example.

For me:
Capture Sharpening -- is usually done during RAW conversion or on the resulting tiff conversion image. This is only a very minor sharpening, in fact should only be barely noticed when zoom-ed 1:1... the amount and sharpening method can depend on the camera's ISO setting and the de-mosiac method used for RAW conversion... usually a low amount of USM.

Creative Sharpening -- is usaully done after adjusting a CaptureSharpen-ed RAW conversion image to preference brightness, contrasts, and colors and limited to mid-tones... and may include Local Contrast Enhancement and/or Blur-ing of the uninteresting background visual elements... Again the amounts and methods used depend upon image content, detail, and goals. I tend to favor mid-tone "HSV-V HighPass Local Contrast Enhancement" for landscape/nature images; I tend to favor PWP5's BilateralSharpening for portrait skin smoothing and facial feature sharpening; I tend to favor AdvancedSharpen-Sharpen for needed mid-tone edge sharpening; and I tend to favor a 15 to 20% Sharpen amount whenever during a workflow an image is warped, rotated, or re-scaled.

Output Sharpening -- will comprise: (1) sharpening specifically for an image resized for web display with slight re-adjustments to brightness, contrast, and color to meet presentation goals; or (2) sharpening specifically for a Canon S820 printer, 4x6 or 8x10 prints and Canon Photo Paper Pro 8-1/2x11 paper with slight re-adjustments to brightness, contrast, and color to meet presentation goals.

[den]

Finally found it!...

Here is a link to a link to Chapt 7 -- Multipass Sharpening by GMitchell of The Lights Right Studio, a 5MB pdf download: http://www.thelightsright.com/MultipassSharpening that also may be of interest...

Read for the general quidelines, not necessarily for specific PS settings to emulate in PWP.

[Martinc]

Thanks Den

Got a bit of reading to do there, ill let you know how I get on.

M

[gonzuller]

Hi Den:

When time permits, a posting on your web site with examples of each of these three stages would be most helpful. I have benefited greatly from your tutorials in the past.

Thanks,
Chris

[den]

Chris...

Capture and Output sharpening are specific to one's camera and output medium. The GMitchell and BFraser references offer more in these areas technically than I can...

You may find that when preference tone/color adjustments are achieved that little or only minor Creative sharpening may be necessary as changes in tone/color contrasts will bring out image detail.

The main thing to remember when using multiple sharpening techniques is not to over-do any one phase so that if undesireable artifacts are created that they are not magnified in a succeeding technique...

Then too... understand that multisharpening processing does not lend itself to bulk image processing!

[den]

Chris... Others:

If of interest, I posted this re HighPass LCE & Sharpening which tends to be part of my 'creative sharpening' workflow.

A detailed workflow for HighPass LCE [Local Contrast Enhancement]/EdgeSharpen-ing limited to mid-tones with no color shifts for 3474x2413 pixel, 48 bit color, 46MB images using PWP3.5.0.10 or later follows:...

http://www.dl-c.com/discus/messages/2/12700.html

[den]

Would there be any interest in my posting a mid-tone LCE/EdgeSharpening workflow sequence using PWP5's BilateralSharpen transform?

I hesitate because it takes 2 minutes to compute the needed 'Mean Image' for a 3474x2413 pixel, 48-bit color, 46MB image with my dual-core processor at the suggested Blur Radius/Threshold... however, the results significantly improve image clarity/detail without apparant tone or color artifacts.

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.

[MikeG]

Den,

It it's not too much trouble, I'd like to try it out. Even if I find that it takes it too long for 'standard' use it may be very worthwhile on photos for which time is no object.

Mike.

[bot]

Den,

I second MikeG´s proposal. I have been experimenting a bit with bilateral sharpening, but do not yet fully understand this transform. Besides being of practical use, I expect that your workflow, as always, will increase my understanding. And, after all, what is 2 minutes?

regards

Ben Bot