# To sharpen or not to sharpen



## tecboy (Jan 7, 2014)

Do you sharpen you images with Lightroom or Photoshop even the image looks very sharped?


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## deeky (Jan 7, 2014)

Only as much as needed for what I want.  Others will certainly correct me if I am wrong, but I believe sharpening is one of those 'destructive edits'.  Use it to get what you want, but use a light hand if you don't need it.  But that probably applies to all edits - why do it if it isn't needed.


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## tecboy (Jan 7, 2014)

Don't know.  Just wonder what is the purpose to sharpen the image?


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## robbins.photo (Jan 7, 2014)

deeky said:


> Only as much as needed for what I want.  Others will certainly correct me if I am wrong, but I believe sharpening is one of those 'destructive edits'.  Use it to get what you want, but use a light hand if you don't need it.  But that probably applies to all edits - why do it if it isn't needed.



You are wrong wrong wrong wrong wrong!!!!!

Ok no not really, just kidding there.. lol.   As far as sharpening is concerned, if the image looks a little soft I will apply a sharpening filter to it, perhaps as much as a second pass on the standard sharpening filter in photoshop.  Anything more than that and the image starts to really degrade.  You can also use an unsharp mask and get pretty good results with it, here's just one quick introduction article, there is a ton more out there about unsharp mask:

Unsharp Mask: How Do You Actually Use That Thing? | Photojojo

And here's another site with some info on some various other sharpening techniques:

Sharpening in Photoshop -- Part III


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## KmH (Jan 7, 2014)

> *To sharpen or not to sharpen*



Sharpen. Every digital photo you make.

I have ACR (Camera Raw/LR) set up to do light, global 'capture' sharpening to every image I edit.
Then I pretty much always do some local, or 'creativ'e sharpening, and then do a final 'output' sharpening based on how the image will be used.
Images destined for printing can usually handle more sharpening than can images destined for electronic display.
So I have a 3 stage approach to sharpening - capture sharpen, creative sharpen, output sharpen.

Are you talking about globally sharpening an image or only doing local sharpening in parts of an image.
Also edge frequency in an image has a lot to do with how much, and what kinds of sharpening can be done.
Sharpening is all about controlling edge halos because the halos determine how sharp an edge will look.

If you want to learn more about sharpening, these guys wrote the software that is ACR's sharpening panel - Real World Image Sharpening with Adobe Photoshop, Camera Raw, and Lightroom (2nd Edition)


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## vipgraphx (Jan 7, 2014)

IF you shoot RAW its almost a given because RAW files are digital negatives and all though when it opens up in camera raw or what ever else you use it uses the default settings. Sometimes they are good and sometimes they need just a bit more. 

What I normally will do if I need to sharpen I have created an action in photoshop that will apply sharpening mask. It is very effective and does not put out as much gain in the image like sharpening in camera raw&#8230;.then I will mask out areas that really do not need it.

BUt to answer your question not always does the image need sharpening.


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## Gavjenks (Jan 8, 2014)

Always sharpen always every time always.  Sharpen. Always.

It's a surprisingly complex topic on how to do it optimally, though, annoyingly. If you really get into it, you can spend quite a lot of time doing it just so, and use a lot of advanced stuff.  But a sort of quick, but still principled way of doing it that I find works pretty well is the following, in photoshop:
1) Go to the "unsharp mask" filter.
2) Slide up the %age as high as it goes (500%) temporarily.
3) Now slide the bottom slider around until you get to the point where you juuuuust begin to see lines that weren't actually there in the scene (the "halos" that KmH refers to). Pick a spot that has fine details in it for purposes of seeing this. Don't worry if it looks nice just yet, only look for the point where artifacts begin to occur.  Leave the slider barely below that point. This will vary WILDLY based on content and how much cropping you did, your resolution, your camera, your noise, etc.
4) Go back and crank down the %age to wherever you think it looks good (usually 100-200ish range for most pictures is what I like. Step 3 is where most of the variation is, this one is more consistent after that)

It's almost impossible to get bad looking sharpening this way, and yet it usually makes a quite noticeable positive difference in the image.


Don't just use auto sharpening filters, etc. Every image demands slightly different tunings, even with the same equipment (a field of grass or corrugated roofing will demand less sharpening probably than a normal scene, since the fine details can easily start looking tacky.  And a glamour portrait, of course, demands less sharpening for style). Auto filters are fast, but you're selling yourself short and risking obvious visible artifacts, or ineffective sharpening.

Sometimes, you will want to sharpen different areas in the image separately. A good example is a brick building against a bright clear sky - halos around the edge are probably going to be super visible and distracting, but you still want to sharpen the brick texture, perhaps, so just select the building slightly inside of it's borders, and sharpen, then sharpen the rest more lightly.


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## weepete (Jan 8, 2014)

Yep, I do. I mostly shoot raw, so it tends to need it. I'll also put a little extra sharpening on jpegs too in Lightroom. In Lightroom all your edits are non destructive, it's the way the software is set up and why it's so useful, though I'm not sure about other programs. 

There's only two scenarios where I can think of where I wouldn't apply it and that is :
A- if even a small amount of sharpening makes the photo look worse
B- if I intensionally want it to be soft

But that's not very often as I'm quite fond of using the masking feature Lightroom pretty heavily so it's only edges that sharpening is applied to


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## Tinderbox (UK) (Jan 8, 2014)

I never use sharpen on my RAW`s , it because i use an noise filter on virtually every image as they seem too dark to me and when i brighten them up i get a lot of image noise and sharpening would be counter productive.

John.


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## manaheim (Jan 8, 2014)

A little more explanation might be warranted...

Almost all digital cameras have an anti-aliasing screen over the sensor.  This intentionally blurs the picture so that the colors "spill over" onto the other individual photosensors. The reason for this is simple... it's an analog world, and a digital camera tries to turn it into X by Y pixels. When you do that, you basically turn all those nice curves and subtle variations into jagged lines.

Therefore, you need to sharpen it slightly in order to get some of that detail back.

There are some cameras that DON'T have the AA filter. Namely the D800E. I don't know of any others off the top of my head... they're rare. They almost all have it.


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## SCraig (Jan 8, 2014)

manaheim said:


> ...I don't know of any others off the top of my head... they're rare. They almost all have it.


Nikon D7100 as well.


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## CaptainNapalm (Jan 8, 2014)

I sharpen all my images to the needed degree.


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## DaPOPO (Jan 8, 2014)

I sharpen textured spaces. I sharpen hair and eyes. If I look at the picture and decide that area needs to be focused on by the eye.. I sharpen it.


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## AndyjO (Jan 8, 2014)

Tinderbox (UK) said:


> I never use sharpen on my RAW`s , it because i use an noise filter on virtually every image as they seem too dark to me and when i brighten them up i get a lot of image noise and sharpening would be counter productive.
> 
> John.



Hi Tinderbox,

Your post reminded me of something I do in post production - i'm very interested in HDR imaging and I like to sharpen my images using Lightroom _but _I use a handy plug-in called *HDRinstant*. I was filming at my local docks late december and I extracted the following image from some video footage. As you can see, it is quite noisy (especially the boat):




I then used the aforementioned plug-in and I stacked the images which greatly reduced the noise as you can see in the following photo below:



I increased the shadows and the blacks and changed some other parameters but I think the image is pretty nice (apart from the mark on the lens...).

What do you think?

Andy


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## amolitor (Jan 8, 2014)

I sharpen somewhat haphazardly. Some pictures are just plain soft to start with, and I don't want a high acutance look. If I am intending to print, I try to remember to oversharpen a little, since printers tend to remove sharpness to a degree, roughly.


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## Braineack (Jan 8, 2014)

Gavjenks said:


> Always sharpen always every time always.  Sharpen. Always.



pretty much this.  I always sharpen.


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## amolitor (Jan 8, 2014)

So you guys who always sharpen, you're sharpening with appropriate parameters for the final output, right?

I mean, just sliding the lever over to 5 or whatever, or even until it looks good in your editor is irrelevant. If you're resizing to whatever for the web, you need to sharpen for that size. If you're printing 8x10, you should sharpen differently, and so on.


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## Braineack (Jan 8, 2014)

There's always some applied by default when i import into LR, but I'll bump it arbitrarily until I'm happy with it in screen.  I'm a fan a sharp/crisp images.


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## apaflo (Jan 8, 2014)

amolitor said:


> So you guys who always sharpen, you're sharpening with appropriate parameters for the final output, right?
> 
> I mean, just sliding the lever over to 5 or whatever, or even until it looks good in your editor is irrelevant. If you're resizing to whatever for the web, you need to sharpen for that size. If you're printing 8x10, you should sharpen differently, and so on.



Size makes a difference, yes. But so does the type of detail in the image.  There is no cookie cutter solution, and knowing which type of sharpening to use is important.  In any case sharpening should be done  "by inspection", and that should be while viewing a 100% crop.  Anything else is your "irrelevant"!

Edit:  And *every* image taken with a Bayer Color Array camera can benefit from appropriate sharpening.


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## ph0enix (Jan 8, 2014)

SCraig said:


> manaheim said:
> 
> 
> > ...I don't know of any others off the top of my head... they're rare. They almost all have it.
> ...



...and the D5300.


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## Braineack (Jan 8, 2014)

and d3300


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## The_Traveler (Jan 8, 2014)

apaflo said:


> amolitor said:
> 
> 
> > So you guys who always sharpen, you're sharpening with appropriate parameters for the final output, right?
> ...



^that


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## Gavjenks (Jan 8, 2014)

amolitor said:


> So you guys who always sharpen, you're sharpening with appropriate parameters for the final output, right?
> 
> I mean, just sliding the lever over to 5 or whatever, or even until it looks good in your editor is irrelevant. If you're resizing to whatever for the web, you need to sharpen for that size. If you're printing 8x10, you should sharpen differently, and so on.



Yes, I sharpen individually to each photo by eye, and using the 100% view. But the order rarely if ever matters with resizing.

One of these was sharpened and then resized. One was resized and then sharpened. I picked numbers in unsharp mask that maintained roughly the same ratio of resize:sharp ratio, so that they should be equivalent, except for the order of those two steps (It's not EXACTLY mathematically precise, because photoshop only lets  you go in increments of 1/10th of a pixel, so the exact ratio wasn't possible, but pretty darn close).  Can you tell me which one is which? Both have had a pretty decent amount of sharpening done to them. More than I would probably normally do, to help highlight any differences.




If you click on them, load each, then use "next" and "previous" you can view them overlaying each other back and forth.


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## amolitor (Jan 8, 2014)

Order shouldn't matter much, but the parameters used do depend on the output size and device.

Essentially, unsharp mask boosts the higher spatial frequencies, at the expense of lower spatial frequencies. If you then resize to smaller, you are throwing away higher spatial frequency information. The result, if you are careless, if that the entire picture loses contrast. Ooops.

By varying the parameters to match the output size, you boost the highest spatial frequencies in the final output, and thus produce a sharper-looking picture in the final output.


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## Gavjenks (Jan 8, 2014)

I'm still not understanding what you mean here.  If it "[considering output size] produces a sharper-looking picture in the final output," then you should be able to tell me which of those two images looks sharper.

To me, they look completely identical, to the point where I wasn't even sure if the "next" and "prev" buttons were functioning correctly.  _And yet one of them was sharpened without any consideration whatsoever to the final output size.




_I.e., if "order doesn't matter much" then that's just another way of saying "you don't need to worry about the output size when you do the sharpening"


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## manaheim (Jan 8, 2014)

I do smart sharpen and drag all the sliders to the extreme right.

It looks wicked pissah.


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## apaflo (Jan 8, 2014)

Gavjenks said:


> Yes, I sharpen individually to each photo by eye, and using the 100% view. But the order rarely if ever matters with resizing.
> 
> One of these was sharpened and then resized. One was resized and then sharpened. I picked numbers in unsharp mask that maintained roughly the same ratio of resize:sharp ratio, so that they should be equivalent, except for the order of those two steps (It's not EXACTLY mathematically precise, because photoshop only lets  you go in increments of 1/10th of a pixel, so the exact ratio wasn't possible, but pretty darn close).  Can you tell me which one is which? Both have had a pretty decent amount of sharpening done to them. More than I would probably normally do, to help highlight any differences.



They are distinctly different!  The B image has higher contrast (it is probably over sharpened).  The problem though is not what either one actually looks like, but getting exactly what you prefer. I can make the A image look exactly like the B image.  The B image is going to lose some of the highlights, so it isn't reversible.  But with the original it would be extremely easy to downsize and then duplicate either of those, while it would be much more time consuming to sharpen first and downsize second trying to get exact duplicates.

The second one probably should have been slightly reduced in brightness before sharpening was applied.  The increase in contrast towards to black end of the scale appears to be a good thing, but at the lighter end too many pixels are just a hair too bright.  That of course is an opinion, and someone else might like it a lot more if the contrast were increased even further!

 The point is that they aren't actually the same at all, and moving one in the direction or the other would be much easier after the image is resized.  It would also be a lot easier if any form of a high pass filtered Sharpen tool were used, simply because USM is not reversible.  Hence the oversharpening of the B image, using USM, can't really be corrected exactly, while adding a little more to the A image to make it like B is probably not hard.

You have a fairly interesting example too!  It has perhaps more single edge transitions, which USM works on, than not. So USM will certainly show an effect.  It also, in all of those leaves, has a great deal of repetative fine detail that a Sharpen tool will be more effective.  To try something fairly subtle, reduce the brightness by about one fstop, and then apply a small amount of Sharpen.  The trick is to use just enough Sharpen to get the desired increase in sharpness of the leaves, but the brightness has to be reduced enough that when that amount of sharpen is applied the highlights don't clip.  I tried just 5 points less brightness, then 10, and finally about 20 before the effect was exactly what I wanted.


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## amolitor (Jan 8, 2014)

Gavjenks said:


> I picked numbers in unsharp mask that maintained roughly the same ratio of resize:sharp ratio, so that they should be equivalent, except for the order of those two steps



Assuming I understand what you mean here, you have performed this correctly. While you may not have thought through what the "correct amount" is, you arranged to arrive at the same place, by adjusting parameters.

If, on the other hand, you blindly applied unsharp mask with radius X, percentage Y, and threshold 0 to both the original and to a shrunk copy, the results should look different.

The point is that if you're sharpening to accomplish a particular goal, rather than simply as a Cargo Cult "I must always sharpen" ritual, then there is a proper amount to be sharpening for any particular output size/device. Your goal, whatever it is, cannot really be accomplished without reference to the final output size and device.

ETA: The thumbnails of your two pictures, interestingly, DO look different to my eye (although it's possible that it's some bizarro thing like part of my display being slightly dimmer), but I cannot see any difference in the full sized ones. I speculate that there's some non-visible differences that result in different results after resizing and recompressing or something.


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## apaflo (Jan 8, 2014)

amolitor said:


> Order shouldn't matter much, but the parameters used do depend on the output size and device.
> 
> Essentially, unsharp mask boosts the higher spatial frequencies, at the expense of lower spatial frequencies. If you then resize to smaller, you are throwing away higher spatial frequency information. The result, if you are careless, if that the entire picture loses contrast. Ooops.
> 
> By varying the parameters to match the output size, you boost the highest spatial frequencies in the final output, and thus produce a sharper-looking picture in the final output.



That is true for a Sharpen tool, but not for an Unsharp Mask tool.  USM will do different things to an image with more pixels.

Also when an image is downsampled to make it smaller that is a very sharp cornered low pass filter... and it simply removes all high frequency spatial detail above the cutoff frequency.  And of course that is exactly the detail that Sharpen and USM amplified to make the image look sharper!  Hence downsampling necessarily removes significant amounts of sharpening.

USM doesn't just boost high frequencies.  It looks for single edge transitions and amplifies the high frequencies in the transition.  At a very short distance from the transition it averages the high frequency spatial values that make the edge sharp.  

Hence if we have a solid area next to an area with a great deal of fine detail, Sharpen will increase the contrast between light and dark areas of the fine detail and will have little effect of the transition from the solid area to the detail.  USM will affect the solid to detailed transition, making it more accute, but at the same time it will slightly blur the fine detail close to that single transition.  Two very different things, though in practice the parameters can and often are adjusted to get almost the exact same effects.


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## amolitor (Jan 8, 2014)

apaflo said:


> USM will do different things to an image with more pixels.



That is pretty much exactly my point. I can't actually tell if you you amplifying my point, or disagreeing with it. But we appear to be, in broad strokes, on the same page either way.


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## Gavjenks (Jan 8, 2014)

amolitor said:


> Gavjenks said:
> 
> 
> > I picked numbers in unsharp mask that maintained roughly the same ratio of resize:sharp ratio, so that they should be equivalent, except for the order of those two steps
> ...



You're contradicting yourself (possibly because I haven't been clear about what I was doing."
"You have performed this correctly" and "it cannot be accomplished without reference to the final output size" are incompatible statements, because *I literally hadn't even decided what the final output size was going to be yet* when I was doing the "sharpen first" image of these two.  So there was absolutely no reference to the final output size while sharpening. Thus, you have to choose one: Either I was doing it wrong, or it CAN be acocmplished without reference to final size.

There is a middle ground between "Blindly applying an action" and "Taking into accoutn the final size."  I am in that middle ground: I am very much taking into account the particular photo I am sharpening and its spatial frequencies. But I am doing so at whatever size it happens to be when I sharpen it.  As long as you do that, you can then go ahead and downrez it to any size you want, and end up with pretty much the exact same output as if you had downrezzed and then sharpened according to its spatial frequency at that point.  There's no reason why you have to have a specific downrezzed size in mind while sharpening before, though. It doesn't factor into any of the parameters.



> Hence downsampling necessarily removes significant amounts of sharpening.


Yes but this is equivalent to simply using a smaller radius after downrezzing, more or less.  "Applying more and then throwing some of the data out" versus "applying less later"
What do I care? It's not like I'm doing the calculations by hand and just wasted 2 months of math or something.



> The B image has higher contrast (it is probably over sharpened).


I think you're right. The problem here is that a perfect experiment is almost impossible, since the limits on the increments you can choose on the slider are very difficult to match. At least it would be too difficult to bother with IMO. 
In the "sharpen after resizing" situation, the radius that worked was on the order of 0.2-0.3 pixels, and the ideal match would have been about 0.25.  I chose 0.3, which perhaps you are actually able to see.  If I had chosen 0.2 though, it would have been undersharpened slightly...

Which actually leads me to a disadvantage of sharpening after resizing, simply due to software logistics: You can't fine tune it as well!


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## apaflo (Jan 8, 2014)

amolitor said:


> apaflo said:
> 
> 
> > USM will do different things to an image with more pixels.
> ...



The statement that USM boosts higher frequencies is true of Sharpen, across the board.  In it's most primative form that is all it does.  Smart sharpen tools and others that do edge detection use other ways to mask what areas are operated on are only slightly different.

USM however will amplify some high frequencies, blur others, and ignore some.  That is the primative form, and again might be modified by use of various masking techniques.

Sharpen is a precisely reversable algorithm.  The same basic algorithm can be either a blur or a sharpen tool by just changing the parameters.

USM cannot be reversed with another algorithm.  The data that is left behind does not indicate what it was derived from.

They are very different in those respects.  The specific point is that if you apply sharpen to a data set, the resample it to a smaller size there is a specific effect, and that can be recreated exactly by doing them in the reverse order (using appropriate parameters).  But that cannot be done with USM.  The order makes a significant difference in how the data is changed.  It is not possible to use USM first on one copy of an image which is then downsized to get the exact same result (as is possible with Sharpen) that will happen by downsizing first and then using USM (even with adjusted parameters).

But yes, generally we are pushing the same concepts for how and when to sharpen, and we're pretty much on the same page!


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## apaflo (Jan 8, 2014)

Gavjenks said:


> There is a middle ground between "Blindly applying an action" and "Taking into accoutn the final size."



Perhaps that isn't the right way to take into account the final size!  Sharpening is best done by inspection.  That is, looking at the results. Because the kind of image detail, as well as the dimensions, is significant it isn't possible to sharpen at one size, calculate the right sharpening parameters for a different size and apply that before reducing the size by the specified amount.  On images where that does work it simply isn't efficient, compared to reducing the size and then applying sharpening by inspection.



Gavjenks said:


> > Hence downsampling necessarily removes significant amounts of sharpening.
> 
> 
> 
> Yes but this is equivalent to simply using a smaller radius after downrezzing, more or less.  "Applying more and then throwing some of the data out" versus "applying less later"



That isn't the same!  It can be rather difficult to get an exact match for the effects of "radius" as opposed to "amount".  Part of the reason for that is very few programs allow you to adjust the "sigma" parameter, which is weighting on how the "radius" is applied. Specifically sigma is the standard deviation of the Gaussian, and adjusts the effect that pixels near/far from the center pixel will have on how much that center pixel is adjusted.  If sigma is small then an increased radius has no effect.  If sigma is large then all pixels withing the radius have the same effect.




> What do I care? It's not like I'm doing the calculations by hand and just wasted 2 months of math or something.


And that is what it would take to get it right!  It's just a lot easier to be able to make the right adjustment by observing the effect, and then get exactly that effect when it is applied.



> > The B image has higher contrast (it is probably over sharpened).
> 
> 
> I think you're right. The problem here is that a perfect experiment is almost impossible, since the limits on the increments you can choose on the slider are very difficult to match. At least it would be too difficult to bother with IMO.
> ...



I don't think finer than tenths is significant, and at least with the tool I use the amount parameter can be adjusted by hundreths.  I definitely agree that implementation makes a huge difference!  I've looked at maybe dozens of sharpening plugins for GIMP, and have compared them to ImageMagick tools as an example.  ImageMagick has perhaps some of the best tools available for many purposes, but for sharpening it is just too difficult to observe the differences when making fine tuning adjustments; hence good or not, I don't use it.


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## Gavjenks (Jan 8, 2014)

(I assume you're talking about this when you say sigma, usually called a "sigmoid"?):


The parameters that photoshop, for instance, gives you are radius and "amount" which i assume is magnitude. Radius (or rather diameter) is going to be the distance between that center point in the above image and the other center point in the mirror image curve on the other side of the kernel.  Amount is just going to be how stretched this whole thing is vertically.

But in practice, changing the amount and *then* going in and changing your curves to be less contrasty = the exact same thing at the end of the day as what you would get if you were able to just change the sigmoid directly.  So it's not really necessary as a tool. Although it would be convenient, it would be redundant.

And none of it is really pertinent to before resizing vs. after.  As long as you scale your radius to the current size, it is identical either way, mostly.  The only reason it isn't *perfectly *identical is simply because we are working in a pixelated space, not a continuous mathematical one, and so there are tiny rounding errors.  That's it. But rounding errors are virtually never going to be noticeable, unless like me, your program gets down to the point of not having enough precision to choose from (thus magnifying rounding errors).

I can't imagine any situation where it would ever make any important difference, though, even with the rounding errors you get with 1/10th pixel precision. The scale of such rounding errors is simply too small to give a hoot about, even if you may technically be able to see them if you stare hard enough. Unless of course you keep doing the filters over and over, which you should generally never do with ANY edit.


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## amolitor (Jan 8, 2014)

I am going to leave the two of you to enjoy yourselves. This is the kind of thing you guys like, and I don't.


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## tecboy (Jan 8, 2014)

Despises my intellect, I have no idea what are they talking about.


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## amolitor (Jan 8, 2014)

tecboy said:


> Despises my intellect, I have no idea what are they talking about.



Neither do they, it turns out. So, it's ok.


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## Gavjenks (Jan 8, 2014)

I do actually sort of do sigmoid math for a living as it turns out! Although nothing to do with photography, it still is the same principle (I use sigmoids and kernels to simulate fields of organized neurons communicating in pattern, which as it turns out is extraordinarily similar to sharpening algorithms) =)


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## bc_steve (Jan 8, 2014)

I sharpen every image, as much as is needed for each one -- basically to the point where increasing the sharpening no longer makes it looks better.  Using high quality glass though like the 70-200 f/2.8, I don't feel like I need to sharpen nearly as much as I used to.

It is also good practice to selectively sharpen, especially images with a shallow depth of field.  There's no point sharpening something that is supposed to be out of focus.  It just adds noise and harshes up your bokeh.


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## apaflo (Jan 9, 2014)

Gavjenks said:


> (I assume you're talking about this when you say sigma, usually called a "sigmoid"?):



 That's close enough.  The parameter is referred to as "sigma", it is used in a sigmoid function that weights how much the "amount" parameter is applied over the distance of the radius.



> The parameters that photoshop, for instance, gives you are radius and "amount" which i assume is magnitude. Radius (or rather diameter) is going to be the distance between that center point in the above image and the other center point in the mirror image curve on the other side of the kernel.  Amount is just going to be how stretched this whole thing is vertically.
> 
> But in practice, changing the amount and *then* going in and changing your curves to be less contrasty = the exact same thing at the end of the day as what you would get if you were able to just change the sigmoid directly.  So it's not really necessary as a tool. Although it would be convenient, it would be redundant.



 Not quite.  The effect on the center pixel from pixels out to the radius distance is  weighted by the value of sigma.  If sigma is as larger or larger than the radius then all pixels within radius distance have equal effect.  If the sigma value matches half the radius then the most distant pixels have less effect and the closest ones have maximum effect.  As the value of sigma becomes small in comparison to the radius it is very much the same as making the radius very small instead.  But the curve of, for example, a specific radius and equal sigma cannot be matched with any smaller value for sigma no matter what the radius is.

Hence sigma is not redundant in theory.  In practice that much control is obviously beyond the needs or understanding of the vast majority of users.  So while not redundant it does have questionable value compared to the added complexity.



> And none of it is really pertinent to before resizing vs. after.  As long as you scale your radius to the current size, it is identical either way, mostly.


That is true of Sharpen, but not for Unsharp Mask, in terms of the effect it has on the image data.

But that doesn't reduce the distinction between using just some random "that will be good enough" amount of sharpening, which is all that can be done with sharpen first and resize second, compared to resize first and then sharpen by inspection to get a precisely correct adjustment.


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## Gavjenks (Jan 9, 2014)

> Hence sigma is not redundant in theory. In practice that much control is obviously beyond the needs or understanding of the vast majority of users. So while not redundant it does have questionable value compared to the added complexity.


Sigma is not redundant with (radius + amplitude).
Sigma is redundant with (radius + amplitude + the curves tool). Ctrl-M in photoshop

Changing the amplitude of sharpening changes both what would be the sigma + the contrast at the same time.  But then by using curves, you can negate the effect on contrast, thus leaving you with just a change to sigma.
So having sigma be an actual slider would be more convenient, but not actually more control than you have already.

You even said it in the first response that the main noticeable thing that seemed wrong was "too high of contrast," intuitively picking out that exact relationship.


(roughly)

Perhaps Unsharp mask doesn't quite do what I am guessing it does, but the empirical evidence pretty much suggests that this is roughly what's going on, as I would expect if it does. Yes, one's a local effect and one's a global effect, and doesn't actually look just like that diagram, but it still pretty much works if you go in that order. Probably not the other order.


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## apaflo (Jan 9, 2014)

Gavjenks said:


> > Hence sigma is not redundant in theory. In practice that much control is obviously beyond the needs or understanding of the vast majority of users. So while not redundant it does have questionable value compared to the added complexity.
> 
> 
> Sigma is not redundant with (radius + amplitude).
> Sigma is redundant with (radius + amplitude + the curves tool). Ctrl-M in photoshop



I'm speaking *only* about the algorithm used to sharpen.  With either USM or an HP Sharpen there are actually three at least three parameters:  radius, sigma, and amount.  Commonly there is a threshold parameter too, and less often there can be a bias parameter to shift convolution.

Commonly a Sharpen tool might only present the user with selection of a single parameter.  USM usually has radius, amount and threshold.


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## Gavjenks (Jan 9, 2014)

The curves tool is one algorithm for sharpening.  It's just a simple way to do one of the most fundamentally basic sharpening algorithms: contrast masking (rather than making an actual mask layer blah blah you can just mess with the curves and do the same thing, and if you actually use curved curves it works better than a basic mask anyway)

It affects some of the same variables as USM does, and the two influence each other in complementary ways, such that if you have curves + USM (with not all of its parameters), you can still achieve the same end result as if you had a better tool with more parameters given to you. Not perfectly down to the pixel identical, but almost / might as well be.


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## k4j98 (Jan 9, 2014)

The way I see it, in developing photos, we are attempting to do what every p&s  does does to its images. They all have done (a lot of) sharpening done. Now much less is needed when using a good lens, of course.

Also, a soft image can be made sharp, but details remain lacking.


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## Braineack (Jan 9, 2014)

Here's why I sharpen, even for screen:




Happy Julia by The Braineack, on Flickr


vs.


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## apaflo (Jan 9, 2014)

Gavjenks said:


> The curves tool is one algorithm for sharpening.  It's just a simple way to do one of the most fundamentally basic sharpening algorithms: contrast masking (rather than making an actual mask layer blah blah you can just mess with the curves and do the same thing, and if you actually use curved curves it works better than a basic mask anyway)
> 
> It affects some of the same variables as USM does, and the two influence each other in complementary ways, such that if you have curves + USM (with not all of its parameters), you can still achieve the same end result as if you had a better tool with more parameters given to you. Not perfectly down to the pixel identical, but almost / might as well be.



But a curves tool simply changes the tone map.  It does not analyze surrounding pixels and make an adjustment based on what is there.  It just looks at the value of one pixel at a time.


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## Gavjenks (Jan 9, 2014)

So what? It ROUGHLY compensates for the things you were complaining about related to downrezzing (contrast and a slightly less surgical approximation of sigma at the end of the day).  And it's something you always do anyway, so it's not even an extra step (just a slightly different curve).

I'm not suggesting that this is perfectly mathematically equivalent. I'm suggesting that if a person is really anal retentive about their sharpening, they can use this as a way of simply _more closely_ approximating the look of sharpening after downrezzing, without having to fuss around with re-editing the stupid image every time they want to print it at a different size.


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## apaflo (Jan 9, 2014)

Gavjenks said:


> So what? It ROUGHLY compensates for the things you were complaining about related to downrezzing (contrast and a slightly less surgical approximation of sigma at the end of the day).  And it's something you always do anyway, so it's not even an extra step (just a slightly different curve).



But it *doesn't*!  It has nothing to do with the sigma parameter used by a sharpen tool.  There was no suggestion that downsizing changes the tone map.  The curves tool is not something that should always be done anyway.



> I'm not suggesting that this is perfectly mathematically equivalent. I'm suggesting that if a person is really anal retentive about their sharpening, they can use this as a way of simply _more closely_ approximating the look of sharpening after downrezzing, without having to fuss around with re-editing the stupid image every time they want to print it at a different size.



Except that a curves tool does not sharpen an image.   And if used to increase contrast between some set of tonal values, there is no way to avoid  that it will also decrease contrast between another set of values.  The curves tool just isn't related to the topic of sharpening.


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## amolitor (Jan 9, 2014)

Just a little meat to keep you guys interested and going at it, because it's so fun to watch you wandering around in the weeds, sigma is a parameter for blurring, nor sharpening. It's the standard deviation of the ideal Gaussian used in a blurring step, which may or may not be part of a sharpening operation. Some sharpening operations use a blurring step, some do not.


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## The_Traveler (Jan 9, 2014)

you two need to get a room.


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## Gavjenks (Jan 9, 2014)

Curves does sharpen by itself. It does it slightly differently, but the end result is a sharper looking line, if so desired.  Usually in addition to different contrast as well.
Normally that's an inefficient way of going about doing things.  But if you're in a situation where the contrast and the sharpening both need changing in the right direction *anyway *(like this one), it works just fine to use a tool that changes both at once.



#2 and #4 are not the same edge.  But they will look a lot more similar than #1 and #2.  Hence "roughly" approximates, as I've been saying.
They will have different flavors, but they will all look sharper then the one on the far left.  Call it strawberry sharpening and chocolate sharpening, whatever.

Also, in your brain, #2 and #4 will look more similar, because *your brain already does unsharp masking* to all edges. And it does it more aggressively when the gradient of an edge is sharper (such as #4 versus #1 or even #3 vs. #1), thus, the actual perception of Edges #2 and #4 will look more like this:


Which now suddenly  look even more similar... it's sort of more along the lines of neopolitan vs. chocolate sharpening (chocolate is in everything!) The one that was already USMed will be stronger (and still possibly have a weirder, 2nd order shape to it now), but they will both have that characteristic shape in your perception, since the brain applies that to everything.


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## tecboy (Jan 9, 2014)

I'm placing a bet on Gavjenks for $20.  I have full confidence that he will win the debate.


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## amolitor (Jan 9, 2014)

They both have incredible stamina.


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## tecboy (Jan 9, 2014)

amolitor said:


> Just a little meat to keep you guys interested and going at it, because it's so fun to watch you wandering around in the weeds, sigma is a parameter for blurring, nor sharpening. It's the standard deviation of the ideal Gaussian used in a blurring step, which may or may not be part of a sharpening operation. Some sharpening operations use a blurring step, some do not.



I thought they were talking about Sigma Lenses.


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## apaflo (Jan 9, 2014)

amolitor said:


> Just a little meat to keep you guys interested and going at it, because it's so fun to watch you wandering around in the weeds, sigma is a parameter for blurring, nor sharpening. It's the standard deviation of the ideal Gaussian used in a blurring step, which may or may not be part of a sharpening operation. Some sharpening operations use a blurring step, some do not.



Blur and Sharpen are essentially the same algorithm, with different values for the same set of parameters.  Adjust them this way and it blurs the image, adjust them that way and it sharpens the image.

 Unsharp Mask does use a blurring step. The high pass filtering of a Sharpen tool does not use a blurring step.  The algorithm for a high pass sharpen has a sigma parameter, though the user might not be able to set it.

The sigma parameter is actually a parameter for a Gaussian Kernel generator and adjusts the Gaussian Curve used.  Sigma is specifically the value for the distance from the center to a point at which the curve is 1/2 the peak value.  Any algorithm that uses Convolution necessarily has a sigma parameter, even if the user does not specifically set it.

Hence *every* tool that uses convolution has a sigma parameter.  Most sharpen tools use convolution, as do tools for blur and edge detection,

 A couple cites:

Bluring and Sharpening -- IM v6 Examples

"Sharpen Arguments? (expand)

The most important factor is the sigma.  As it is the real control of the sharpening operation."

High-Pass Filtering (Sharpening)

"High-Pass Filtering (Sharpening)

A high-pass filter can be used to make an image sharper.  These filters emphasize fine details in the image - exactly the opposite of the low pass filter. High-pass filtering works in exactly the same way as low pass filtering. It just uses a different convolution kernel."


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## amolitor (Jan 9, 2014)




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## amolitor (Jan 9, 2014)

I actually understand what sigma is and how it is used in USM just fine, thanks.

You use words like 'Blur' and 'Sharpen' as if they were well defined and very specific algorithms, and they are not. They are just words. Probably in whatever tool you use, they mean something very specific, but we don't even know what tool or tools you use, and we certainly don't care. There are a ton of things called 'Sharpen' out there, not all of them use a Gaussian Kernel anywhere.

There's a lot of ways to amplify higher frequencies, or attenuate lower ones, and not all those ways have a thing called "sigma" anywhere in them.


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## amolitor (Jan 9, 2014)

apaflo said:


> The sigma parameter is actually a parameter for a Gaussian Kernel generator and adjusts the Gaussian Curve used.  Sigma is specifically the value for the distance from the center to a point at which the curve is 1/2 the peak value.  Any algorithm that uses Convolution necessarily has a sigma parameter, even if the user does not specifically set it.
> 
> Hence *every* tool that uses convolution has a sigma parameter.  Most sharpen tools use convolution, as do tools for blur and edge detection,



This is complete nonsense. This so-called "definition" for sigma is not only wrong, but only makes sense for fairly specific convolution kernels.


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## apaflo (Jan 9, 2014)

Gavjenks said:


> Curves does sharpen by itself.



Not by itself!  It changes the tone map of the entire image, not just specific edge transitions.

You can sharpen using curves, but it is not particularly effect.  First you have to use an edge detection tool to make an appropriate mask...


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## Gavjenks (Jan 9, 2014)

I'll use that as an example of curves sharpening only.  Looks terrible in this case / there's no real artistic goal of sharpening like this, but it demonstrates that it is quite possible. It looks terrible precisely because, as you say, it isn't masked for edges only, and there's a huge-ass section of the image with no edges AND midtones.


(Photocopier-chic)

But on a normal photo (as long as it doesn't contain a lot of sky OR the sky's tonal range is far away from the majority of midtone edges--which is most photos) it doesn't necessarily look terrible at all, because there usually aren't those huge midtone areas with no edges: 


Notice contrast of course goes up, but so do the lines look sharper as well.  Because all of those indistinct edges in the midtones are made steeper and thus much more visible.  While edges in the highlights and shadows are mostly unaffected (very slightly dulled, but there are also way fewer of them here). And there's no photocopier-chic, because there aren't usually massive smooth gray gradients in real life taking up half the frame.

(Edit: more responsibly done with fewer inflection points)

It still technically will create semi-edges where there were none in smooth midtone gradient areas.  But it doesn't matter, because in practice, all that does is just basically make leaves look a little rounder...




I almost always do this AND unsharp mask, and the two influence one another.  Because this is IMO the most pleasing way to adjust contrast, but since it also sharpens a little bit (more of a side effect in my perception usually), you end up doing a bit less USM than you would otherwise as a result.  The effect of each on the other doesn't require conscious thought, because you're just doing it by eye anyway, but it is happening. And I do always try to choose "peak" points in the histogram to center the curve on, for this reason.


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## apaflo (Jan 9, 2014)

amolitor said:


> There are a ton of things called 'Sharpen' out there, not all of them use a Gaussian Kernel anywhere.
> 
> There's a lot of ways to amplify higher frequencies, or attenuate lower ones, and not all those ways have a thing called "sigma" anywhere in them.



I have repeatedly specified "high pass" and "convolution" methods for sharpen.  And have pointed out that most "Sharpen" tools in image editors use convolution.  As noted, all algorithms using convolution have a sigma parameter, even if the user cannot set it.

Can you cite a Sharpen tool commonly seen in a typical editor that does not use convolution?



amolitor said:


> This is complete nonsense. This so-called "definition" for sigma is not only wrong[...]



 It's pretty standard stuff.  See and also try Gaussian function - Wikipedia, the free encyclopedia and Standard deviation - Wikipedia, the free encyclopedia for definitions and examples.


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## apaflo (Jan 9, 2014)

Gavjenks said:


> I'll use that as an example of curves sharpening only.



I'm sorry, but all you have done is change the gamma curve, increasing contrast in some areas and decreasing it in others.  That is not what "sharpen" means.

Here is a really good article by Roger Cicala of LensRental.com about sharpening.  He does a very good job of describing sharpness, acutance and resolution.


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## amolitor (Jan 9, 2014)

You can and often do convolve with things that are not Gaussian functions. Gaussian things and convolution things are in fact completely separate ideas, that have only occasional and largely accidental overlaps.

Wavelet sharpening.


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## Derrel (Jan 9, 2014)

tecboy said:


> I'm placing a bet on Gavjenks for $20.  I have full confidence that he will win the debate.






Yeah, but the thing is, you just NEVER really "know" for sure...


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## Rick58 (Jan 9, 2014)

Just think, once upon a time you only had to worry about grain and a good enlarger lens.


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## snowbear (Jan 9, 2014)

I like turtles.


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## Gavjenks (Jan 10, 2014)

> Can you cite a Sharpen tool commonly seen in a typical editor that does not use convolution?


Why yes I can! The curves tool in photoshop... =D
As you yourself pointed out, it is one for one pixel for pixel, without consideration of neighbors. I.e. no kernel/convolution.

Also, unsharp mask done in analog is an example of a sharpening tool that does not use a convolution, in a darkroom. (assuming you mean actually calculated on a computer.  It is a convolution in physical space, but if you count that, then everything ever in the universe is a convolution pretty much)



> Just think, once upon a time you only had to worry about grain and a good enlarger lens.


Both unsharp masking and contrast masking can be done analog. Could be having the exact same debate in 1975, interestingly.


> I'm sorry, but all you have done is change the gamma curve, increasing contrast in some areas and decreasing it in others. That is not what "sharpen" means.
> Here is a really good article by Roger Cicala of LensRental.com about sharpening. He does a very good job of describing sharpness, acutance and resolution.


1) (You forgot the link.)
2) That's not a gamma adjustment. Gamma is a specific power equation which is not what I did, and which, importantly, does not sharpen things unlike what I did. Gamma only makes the whole image darker or lighter in a non-linear fashion. Well... I suppose it could SORT OF "sharpen" something if it brings the lightness values from outside the eye's range to inside of it, such that you can see edges you couldn't before.  But I'm not sure I would count that.
3) I did actually perform *every single step* involved in a classic sharpening algorithm.  I first applied a sub-algorithm to choose where the edges were. In this case, that sub-algorithm was me manually looking at the histogram and picking what I thought was the pointiest bit. This serves the same purpose as a blurring mask. In fact, I would go so far as to actually say that what I did WAS a (1-dimensional) mask. it's just cruder.  I then proceeded to apply a curve in the reverse of the gradient of the edge in order to improve its acutance, which is precisely what the USM tool does.  Instead of using a gaussian, however, I simply eyeballed my own curve.  But it serves the exact same purpose, again just more organically and not a strict equation behind it.

And you can't say "Oh it's unfair to offload part of the algorithm to your brain, that doesn't count," because YOU DO TOO when you use the unsharp mask tool. Your brain is choosing each parameter using algorithms of its own, before the computer runs the USM algorithm.  This is no different, just the brain is doing more of it.


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## apaflo (Jan 10, 2014)

amolitor said:


> You can and often do convolve with things that are not Gaussian functions. Gaussian things and convolution things are in fact completely separate ideas, that have only occasional and largely accidental overlaps.
> 
> Wavelet sharpening.



You are the only one who has suggested a Gaussian function is necessary for sharpening, and I pointed out that is not the case.  The reference I gave was to show you how convolution necessarily has a sigma parameter.

Yes, wavelet sharping is an example of a non-convolution form of sharpening!  It's one that is virtually always named differently too...  Another, which probably will not be obviously identified, would be one using a Fourier transform.


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## amolitor (Jan 10, 2014)

apaflo said:


> You are the only one who has suggested a Gaussian function is necessary for sharpening



I did no such thing. I defy you to point out where I said such a ridiculous thing.



apaflo said:


> The reference I gave was to show you how convolution necessarily has a sigma parameter.



Again, convolution does not necessarily have a sigma parameter. You are simply wrong here.

There is not room in the margin of this book to give you a course in digital signal processing, but it is painfully clear that you're operating at least a couple steps past the limits of your knowledge here. It's embarassing.


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## apaflo (Jan 10, 2014)

Gavjenks said:


> > I'm sorry, but all you have done is change the gamma curve, increasing contrast in some areas and decreasing it in others. That is not what "sharpen" means.
> > Here is a really good article by Roger Cicala of LensRental.com about sharpening. He does a very good job of describing sharpness, acutance and resolution.
> 
> 
> 1) (You forgot the link.)



Sorry about that! Here it is: LensRentals.com - Have You Seen My Acutance?



> 2) That's not a gamma adjustment. Gamma is a specific power equation



The specific power equation is "gamma correction". Gamma is a measure of contrast.  Look it up, and almost any dictionary will say it is "a measure of the contrast reproduced in a photographic or television image"



> which is not what I did, and which, importantly, does not sharpen things unlike what I did. Gamma only makes the whole image darker or lighter in a non-linear fashion. Well... I suppose it could SORT OF "sharpen" something if it brings the lightness values from outside the eye's range to inside of it, such that you can see edges you couldn't before. But I'm not sure I would count that.



What you did, using a Curves Tool, was change the gamma curve.  That's what "Curves" does.  And you are correct that changing the gamma curve does not sharpen an image.

"The key concept with curves is that you can never add contrast in one tonal region without also decreasing it in another. In other words, the curves tool only redistributes contrast."
Using the Photoshop Curves Tool



> 3) I did actually perform every single step involved in a classic sharpening algorithm. I first applied a sub-algorithm to choose where the edges were. In this case, that sub-algorithm was me manually looking at the histogram and picking what I thought was the pointiest bit. This serves the same purpose as a blurring mask. In fact, I would go so far as to actually say that what I did WAS a (1-dimensional) mask. it's just cruder. I then proceeded to apply a curve in the reverse of the gradient of the edge in order to improve its acutance, which is precisely what the USM tool does. Instead of using a gaussian, however, I simply eyeballed my own curve. But it serves the exact same purpose, again just more organically and not a strict equation behind it.
> 
> And you can't say "Oh it's unfair to offload part of the algorithm to your brain, that doesn't count," because YOU DO TOO when you use the unsharp mask tool. Your brain is choosing each parameter using algorithms of its own, before the computer runs the USM algorithm. This is no different, just the brain is doing more of it.



I'm sorry, that is so silly as to be laughable.

There is no point in continuing a discussion... That article was just over the top on being absurd.


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## Gavjenks (Jan 10, 2014)

apaflo said:


> The specific power equation is "gamma correction". Gamma is a measure of contrast.  Look it up, and almost any dictionary will say it is "a measure of the contrast reproduced in a photographic or television image"


Look it up? Okay:
Glossary: Gamma: Digital Photography Review <--not an absolute measure, only a relative parameter in a power law equation
Gamma correction - Wikipedia, the free encyclopedia <--not an absolute measure, only a relative parameter in a power law equation
Gamma FAQ - Frequently Asked Questions about Gamma <--not an absolute measure, only a relative parameter in a power law equation
Gamma is undefined for anything other than a curve that fits a power function, which my random wobbly hand-made polynomial curve is most definitely not an example of.



> "The key concept with curves is that you can never add contrast in one tonal region without also decreasing it in another. In other words, the curves tool only redistributes contrast."


Okay, that's nice, so what? I didn't claim to do anything other than redistribute contrast.
I fully admit: I robbed contrast from the areas of the image that didn't have very many edges in them, and give that contrast to the areas that DID have edges in them.  *Otherwise known as sharpening. *Your beloved unsharp mask also conserves contrast, and does the same exact thing, just a bunch of times with weighted outputs. Robbing contrast from non-edged and giving it to edges is what sharpening IS.  The blurring part of USM is just telling it where to do sharpening. The actual sharpening works the same way in principle.

Apparently I need an even more dramatic example.



Just wanna be crystal clear now... your claim is that the middle line is in fact *blurry*, and the line on the right is *sharp*?
Or are they both about equally sharp?
If so, I am interested in what your name is for the process that brings something from blurry to sharp, yet is not "sharpening."







> I'm sorry, that is so silly as to be laughable.


Yes, you're right I'm sorry. Doing math and performing algorithms without an electronic computer is crazy and unrealistic, and there is absolutely no precedent for it at any time during human history. I am ashamed to have brought it up.

Also, I want to come clean on something else... This thing is a totally a hoax, man. Some historians and I made it up in the mid 90s just to screw with people. I sincerely apologize:

(wikimedia commons)


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## EIngerson (Jan 10, 2014)

Sharpen.


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## The_Traveler (Jan 10, 2014)

This is sort of like watching three females argue about whose penis would be bigger if they had one.


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## manaheim (Jan 10, 2014)

*spits out coffee*


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## Rick58 (Jan 10, 2014)

The_Traveler said:


> This is sort of like watching three females argue about whose penis would be bigger if they had one.


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## jenko (Jan 10, 2014)

I do not sharpen every image. It's a case-by-case basis. 

I have been liking the new "camera shake" sharpen in PS CC. It's definitely not for _every_ image, and it needs slider tweaking, but for some shots it works perfectly. 

Other than that, I don't have much to add that has not already been said.


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## EIngerson (Jan 10, 2014)

The_Traveler said:


> This is sort of like watching three females argue about whose penis would be bigger if they had one.


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## amolitor (Jan 10, 2014)

The_Traveler said:


> This is sort of like watching three females argue about whose penis would be bigger if they had one.



Well played, Lew.


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## The_Traveler (Jan 10, 2014)

amolitor said:


> The_Traveler said:
> 
> 
> > This is sort of like watching three females argue about whose penis would be bigger if they had one.
> ...



I mourn for the 1s and 0s sacrificed.


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## amolitor (Jan 10, 2014)

I hate 1s and 0s. 2s, 7s, and 378972s are the only numbers I _really_ like.


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## JacaRanda (Jan 10, 2014)

The_Traveler said:


> This is sort of like watching three females argue about whose penis would be bigger if they had one.



Lew for Prez Jan-Feb 2014!   Fantastic  :lmao:


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## The_Traveler (Jan 10, 2014)

My guess is that a very good and useful essay would come out of accumulating all those comments and normalizing them.
Are the differences of opinion due to different definitions? Are there different concepts that need to be explained?
I am not knowledgeable enough to do the integration but, if the three active commenters could agree to a cease fire, perhaps a enlightening collaborative post could be achieved.

I would be happy to be one of the readers and indicate where areas aren't dumbed down enough.

Lew

*&#8734;*


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## pixmedic (Jan 10, 2014)

I only sharpen when my pencil no longer has enough lead exposed to write. 
After reading this thread though, im not so sure it was ever sharpening to begin with. 
maybe its really just adjusting the curves of the end of the pencil until I get the desired result.
oh wait...that _*is*_ sharpening. 

All this math is giving me a headache...
look guys, all you really need to know is which slider to adjust, and _*boom*_, instant pro photo.


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## amolitor (Jan 10, 2014)

To be honest, I have very little to say on the subject of sharpening as such. There's a lot of wrong in play both in this thread and in the popular ideas about sharpening, but as I am sure everyone knows, there's a huge gap between recognizing that there are problems, and knowing what the solution is.


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## Derrel (Jan 10, 2014)

amolitor said:


> To be honest, I have very little to say on the subject of sharpening as such. There's a lot of wrong in play both in this thread and in the popular ideas about sharpening, but as I am sure everyone knows, there's a huge gap between recognizing that there are problems, and knowing what the solution is.






My vote is to sharpen images on an as-needed basis. There are more sharpening tools available today than ever before.


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## korosh (Jan 10, 2014)

happy new year


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## Gavjenks (Jan 11, 2014)

I for one would have been much more adamant on the issue of DVRing the real housewives.


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## Braineack (Jan 11, 2014)

JacaRanda said:


> The_Traveler said:
> 
> 
> > This is sort of like watching three females argue about whose penis would be bigger if they had one.
> ...




while we are voting, how about worst thread of 2014.


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## Derrel (Jan 11, 2014)

Gavjenks said:


> I for one would have been much more adamant on the issue of DVRing the real housewives.



I suspected as much. ;-)

It's great to see you back on TPF after an absence, Gavjenks. I hope you have been well. And that none of the pipes froze at your during this extreme super-cold streak.


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## Rick58 (Jan 12, 2014)

I'm going to get some coffee. Call me after someone shoots this thread in the head.


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## tecboy (Jan 12, 2014)

What? Debate is over?  I changed my bet to Apaflo.  He was leading away with those internet infos and wikipedia facts.  Darn!


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