Important Sharpening Information!

[Roger Clark]

I'm not sure why multiple passes seems to work so well - but it does.

There is a theoretical reason why it should work, in case you are interested. In Fourier series, all wave forms can be described by a set of sine waves. For example a square response, like the intensity profile of a building in an image would be made up of increasing frequency sine waves, and the higher the frequency used, the better the edge is represented.

In a blurred image, the edges are soft which corresponds to reduced intensity sine waves at high frequency. So when you do multiple sharpening steps, each with decreasing radius, it is like boosting those high frequency sine wave components in the Fourier Transform.

Here is an example of multiple passes I did in 2002:
http://www.clarkvision.com/imagedetail/unsharpmask
(obviously the statement about adding other images: I never got back to it).

Roger

 

[Bill McCrystyn]

Thank you Roger - I am always interested and as an old audio guy, understand your answer. Light, like sound has remarkable similarities. Your example is impressive. I will continue to play with it.

 

[Michael Lloyd]

Hi Bill,

Genuine Fractals 5.0 is a plugin for photoshop that allows you to upsample an image via a process where it applies fractal algorithms to match the original image, then extrapolates those algorithms in the upsampling process. The detail that's "created" closely matches that which is found in everyday things. It simply allows you to specify the new size you want for the image and the image size is changed. It can be pretty slow with large images at high bit depth.

I have no business affiliation with OnOne Software (the makers of Genuine Fractals), by the way.

My dSLR Fractal Sharpen actions upsample the image to 250% of original size with Genuine Fractals, which preserves the crispness of subject edges with minimal "ringing" or "haloing", manipulates the image at the higher resolution to add additional edge crispness, and finally downsizes back to original size. This is incredibly effective for that last little bit of sharpening, such as what is needed with most digital cameras. Here are a couple of before / after images to give you an idea of the results... The first is done with one of my most aggressive actions, Heavy Sharpen Low ISO. The second with a less aggressive one, Medium Sharpen Max Texture. I describe the "feel" of the results as "refined detail", and it's well suited for prints.

Like Bill, I am also very familiar with deconvolution sharpening (I process a lot of astrophotos) and there are limits to what the deconvolution can produce. It's highly dependent on data quality for one thing, and personally I find the results from deconvolution can all too easily get to a point where the image looks overprocessed, especially at the edges of subject material. I worked to avoid that look with my own sharpening actions.

Lastly, I have been experimenting with a technique I call "iterative smart sharpening", in which multiple passes of very light Photoshop Smart Sharpen are applied at slightly decreasing radii. This is proving surprisingly effective.

-Noel

Even with my rudimentary sharpening skills (one pass with Smart Sharpen) I can see a difference when I use GF first. I would love to know what your sharpening steps are as well as how you downsize.

 

[Roger Clark]

I would like to make one more comment regarding up-sampling and sharpening. As a scientist I work with a lot of algorithms regarding sampling and convolution. Every algorithm I have seen has artifacts, and those artifacts get worse the harder you push. But more importantly, no one method consistently does better than another. Many are pretty good and "good enough" for many applications. When you really want to push the limits, try different settings for each algorithm you have, then choose the best parts of each test image and blend those together.

For example, if you want to improve the sharpness of the bird's eyes in an image, you will likely need one set of parameters for your sharpening algorithm, then when if you want to sharpen the bird's feathers that are slightly out of focus, you will need a different set. Optimize the settings for each section of image then dlend those sections together. That's what I did on the image I posted on Aug 30.

Roger

 

[Lance Peters]

Fantastic thread - just goes to show you never stop learning.

Version 6 has been announced and supports CS4 (No 64 bit support) cant wait to see what it can do.
Would be good if some of the guru's in this software would post a mini tutorial.

 

[Lance Peters]

Noel - do you still sell your actions??

 

[Noel Carboni]

Noel - do you still sell your actions??

Sorry I haven't been back here for a long while.

The answer is yes, and I've just made a new version that supports Genuine Fractals 6 and Photoshop CS2 through CS4.

Thanks.

-Noel

 

[Paul Lagasi]

Will the standard Genuine Fractals 6 be enough or do you need Professional Version?

 

[Michael Lloyd]

i use standard and the actions work very well with it.

I've got to give Noel an unsolicited plug. His actions work very well. Especially this newest round. I've seen very good results with them right out of the box (so to speak). I really need to take the time and read through the instructions but this is a bad time of year for that

 

[Jay Gould]

Sorry I haven't been back here for a long while.

The answer is yes, and I've just made a new version that supports Genuine Fractals 6 and Photoshop CS2 through CS4.


Thanks.

-Noel

Noel, just had a peek at your website. The before/after images are amazing. Your stuff is way ahead of where I am; however, no reason not to look waaaaay ahead. Are you tools similar to presets in LR?

Cheers,

 

[Noel Carboni]

Perfect Resize

Wow, I'm remiss for not checking back here in an age... I've been working on plug-in development.To answer your question, Jay, in short: No. I've described what my actions do a bit up-thread. They work in Photoshop only....I just wanted to mention that OnOne Software has released a successor to Genuine Fractals. It's called Perfect Resize 7, and it's all that Genuine Fractals was under the covers and more.I have developed actions that work with Perfect Resize. They're still pre-release, but I do supply them to people who ask, and to people who make new orders. (I guess you could say they're released, though I am still doing some testing to see if I can use some of the new settings to achieve even better results).By the way, OnOne has shown their appreciation to me by giving me a discount code I can provide to my customers... So...If you're looking to upgrade to Perfect Resize 7 and are thinking about buying my dSLR Fractal Sharpen actions, just drop me an eMail. I will be happy to send you the discount code, which will actually save you more than the entire cost of my actions on the OnOne plug-in! -Noel

 

[Noel Carboni]

Perfect Resize (retry of strangely formatted post)

Oops! I'm not sure what happened to the above post - it got all run together. As I don't see an "Edit" link, I'll try sending it again with a different browser. Moderator, please feel free to delete the one above.


Wow, I'm remiss for not checking back here in an age... I've been working on plug-in development.

To answer your question, Jay, in short: No. I've described what my actions do a bit up-thread. They work in Photoshop only.

I just wanted to mention that OnOne Software has released a successor to Genuine Fractals. It's called Perfect Resize 7, and it's all that Genuine Fractals was under the covers and more.

I have developed actions that work with Perfect Resize. They're still pre-release, but I do supply them to people who ask, and to people who make new orders. (I guess you could say they're released, though I am still doing some testing to see if I can use some of the new settings to achieve even better results).

By the way, OnOne has shown their appreciation to me by giving me a discount code I can provide to my customers... So...

If you're looking to upgrade to Perfect Resize 7 and are thinking about buying my dSLR Fractal Sharpen actions, just drop me an eMail. I will be happy to send you the discount code, which will actually save you more than the entire cost of my actions on the OnOne plug-in!

-Noel

P.S., if you've already bought my actions, please write to me anyway. I'll still give you the discount code and the updated actions will be yours free of charge.

 

[Arthur Morris]

I had never seen that Roger Clark pretty much told the world that I was dead wrong in Pane 14 when I wrote this in Pane 13: OK. Here we go. It is absolutley wrong to sharpen your full sized TIFF master files. No digital image should be sharpened until it is sized for final usage. I save my optimized master file. If we need to make a print, we open the master file, duplicate the image, close the master file, size the image to the print size and then sharpen the image.

Roger explained clearly and at great length using scientific terms that most real world photographers have never heard of much less understood.

Then John Chardine wrote in the thread here: http://www.birdphotographers.net/forums/showthread.php/116579-Maintaining-image-fine-detail

Quote Originally Posted by Dick Ludwig View Post

If you downsize an image you should do the final sharpening after you do the downsize, not before.

"

This is a common myth. See this excellent BPN thread (viewed 18,300 times to date):

http://www.birdphotographers.net/forums/showthread.php/18534-Important-Sharpening-Information!

So John was clearly agreeing with Roger who had clearly indicated that I was dead wrong about my original comments. Many folks who are now and may not have been then agreed with Roger;s position. And many thanks Roger for his insightful comments.



Yesterday I wrote friend and digital photograph guru Tim Grey as follows:

Hey Tim,

Hope that all is well. All here is A-OK.

As a matter of course, do you feel that it is best to sharpen your full resolution master files and then downsize them and add additional sharpening? Or you you feel that it is best to save your master file unsharpened and then sharpen the images after sizing for a given use be it a billboard or a small JPEG?

thanks and later and love, artie

Here is his reply:

Artie,

Greetings from Austria!

My general approach is to leave the master image unsharpened, applying sharpening only to derivative images (such as an image created for printing or online sharing). This way, the sharpening is only applied to the image based on the final output size (pixel dimensions).

That said, there is a reasonable argument for applying sharpening in two stages. Very slight sharpening can be applied to the master image to compensate for the slight loss of sharpness inherent in a digital photo. Then, after resizing, output-based sharpening is applied as well. If this approach is taken, it is important that the initial sharpening be very subtle.

But regardless, sharpening should definitely be applied based on the final output size, even if a small degree of sharpening had been applied to the master image previously.

Tim

There are of course two sides to every argument. Whom do you want to believe is right here, a scientist who uses terms that you do not understand or someone on the Photoshop Beta team for more than a decade and a well respected digital photography guru?

I do not mind being told I am wrong when I am actually wrong but that was not the case here. Please do not be fooled by scientific mumbo jumbo, endless rhetoric, and dozens of folks agreeing with a scientist....

Respectfully.

 

[Doug Brown]

I subscribe to Tim's/Artie's approach.
1. Lightroom default sharpening of the RAW file
2. Save an unsharpened master TIFF file
3. Resize the TIFF to output size and then sharpen for the intended use