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#51
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Lenses and sharpening
On 2014-09-16 02:59:40 +0000, Eric Stevens said:
On Tue, 16 Sep 2014 04:36:08 +0200, android wrote: In article , (Floyd L. Davidson) wrote: nospam wrote: In article , Eric Stevens wrote: All adjustments made to *Smart Objects*, in Photoshop terms, are non-destructive. I fully expect you to tell me I am wrong. I will tell you that you are discussing a point which is not the point raised by Floyd. So too is nospam, but that is not surprising. Floyd was referring to a reversible function: run it forwards and you get sharpening; run it backwards and you get blur. Or the other way around if you wish. there are indeed such functions, but that doesn't matter to users. they want to edit photos, not learn mathematical theory. when a user can modify an image and change it later, it's reversible and that's why it's called a non-destructive workflow. Squirm all you like, but USM is well known to be a non-reversible function. Oki... A reversible function and ditto workflow ain't the same thing. ;-) I doubt if nospam can get his mind around that thought. :-( You might have notice that android addressed that comment to Floyd. A non-destructive workflow makes that irreversible function very reversible indeed. Once that working copy has had USM applied, the layers merged, and compressed into a JPEG (a destructive action) then Floyd is correct, the function can no longer be reversed. However, Floyd doesn't see the concept of the non-destructive workflow because he doesn't, or appears not to use one. He certainly isn't using what is available to those running either Lightroom or Photoshop CS6/CC/CC 2014, and ignores that some here have the ability to take advantage of a non-destructive, or "reversible" workflow because of the software tools installed on their computers. -- Regards, Savageduck |
#52
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Lenses and sharpening
In article 2014091522353122268-savageduck1@REMOVESPAMmecom,
Savageduck wrote: A non-destructive workflow makes that irreversible function very reversible indeed. Once that working copy has had USM applied, the layers merged, and compressed into a JPEG (a destructive action) then Floyd is correct, the function can no longer be reversed. However, Floyd doesn't see the concept of the non-destructive workflow because he doesn't, or appears not to use one. He certainly isn't using what is available to those running either Lightroom or Photoshop CS6/CC/CC 2014, and ignores that some here have the ability to take advantage of a non-destructive, or "reversible" workflow because of the software tools installed on their computers. exactly. |
#54
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Lenses and sharpening
On Mon, 15 Sep 2014 23:19:52 -0400, nospam
wrote: In article , Eric Stevens wrote: when a user can modify an image and change it later, it's reversible and that's why it's called a non-destructive workflow. Fine, fine. If you wear a reversible jacket do call it, too, a non-destructive work flow? Of course not. There are several subtly different meanings to the word 'reversible' and you seem to have only learned one of them. floyd would be the one who has only learned one of them. everything in a non-destructive workflow is reversible. that's the whole *point* and why it's so useful. It's your point, but it wasn't Floyds and it's not what I want to discuss. Why don't you shut up? You may learn something. tell that to floyd. he knows nothing about non-destructive workflows or how they work, going so far to say that they are for cartoon characters. You are not listening. You are not thinking either. Just you usual blah blah blah. if anyone needs to learn something, it's him. Whatever it is, you have nothing to teach him. -- Regards, Eric Stevens |
#55
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Lenses and sharpening
On Mon, 15 Sep 2014 22:35:31 -0700, Savageduck
wrote: On 2014-09-16 02:59:40 +0000, Eric Stevens said: On Tue, 16 Sep 2014 04:36:08 +0200, android wrote: In article , (Floyd L. Davidson) wrote: nospam wrote: In article , Eric Stevens wrote: All adjustments made to *Smart Objects*, in Photoshop terms, are non-destructive. I fully expect you to tell me I am wrong. I will tell you that you are discussing a point which is not the point raised by Floyd. So too is nospam, but that is not surprising. Floyd was referring to a reversible function: run it forwards and you get sharpening; run it backwards and you get blur. Or the other way around if you wish. there are indeed such functions, but that doesn't matter to users. they want to edit photos, not learn mathematical theory. when a user can modify an image and change it later, it's reversible and that's why it's called a non-destructive workflow. Squirm all you like, but USM is well known to be a non-reversible function. Oki... A reversible function and ditto workflow ain't the same thing. ;-) I doubt if nospam can get his mind around that thought. :-( You might have notice that android addressed that comment to Floyd. So what? I was agreeing with him. A non-destructive workflow makes that irreversible function very reversible indeed. You are fudging word meanings. In fact you seem to be demonstrating that you too don't know the difference between a reversible function and a reversible work flow. Once that working copy has had USM applied, the layers merged, and compressed into a JPEG (a destructive action) then Floyd is correct, the function can no longer be reversed. However, Floyd doesn't see the concept of the non-destructive workflow because he doesn't, or appears not to use one. He certainly isn't using what is available to those running either Lightroom or Photoshop CS6/CC/CC 2014, and ignores that some here have the ability to take advantage of a non-destructive, or "reversible" workflow because of the software tools installed on their computers. Floyd wasn't even talking about it! He was talking about different sharpening algorithms. -- Regards, Eric Stevens |
#56
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Lenses and sharpening
On 16/09/2014 05:37, John McWilliams wrote:
On 9/15/14 PDT, 7:07 PM, Floyd L. Davidson wrote: Savageduck wrote: I got what Floyd was talking about when he was talking of high pass sharpening, and reversing it by applying the corresponding reverse parameter blur. However, he also stated above, "UnSharpMask is not reversible". My point addressed the fact that for some of us, that is not an entirely valid statement. IN an environment that supports a saved original copy so that all edits are non-destructive then that is true. But the mathematics of blurring and of unsharp masking make it irreversible if you are only given just the processed image. (and not some hybrid Photoshop workflow encapsulated format) That is in fact a valid statement. The USM function is not reversible. That isn't a opinion, it's a fact. For one definition of the word! This seems to have degenerated into a heated and utterly pointless semantic argument over the meaning of "reversible" that is in conflict with normal image processing and mathematical parlance. A mathematical operation is reversible if a strict inverse function exists that can exactly get you back to where you started. Any operation can be made non-destructive simply by saving a copy of the original before applying the irreversible filter but that isn't very interesting. Some packages do support this sort of safe workflow. -- Regards, Martin Brown |
#57
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Lenses and sharpening
On 2014-09-16 08:05:37 +0000, Eric Stevens said:
On Mon, 15 Sep 2014 22:35:31 -0700, Savageduck wrote: On 2014-09-16 02:59:40 +0000, Eric Stevens said: On Tue, 16 Sep 2014 04:36:08 +0200, android wrote: In article , (Floyd L. Davidson) wrote: nospam wrote: In article , Eric Stevens wrote: All adjustments made to *Smart Objects*, in Photoshop terms, are non-destructive. I fully expect you to tell me I am wrong. I will tell you that you are discussing a point which is not the point raised by Floyd. So too is nospam, but that is not surprising. Floyd was referring to a reversible function: run it forwards and you get sharpening; run it backwards and you get blur. Or the other way around if you wish. there are indeed such functions, but that doesn't matter to users. they want to edit photos, not learn mathematical theory. when a user can modify an image and change it later, it's reversible and that's why it's called a non-destructive workflow. Squirm all you like, but USM is well known to be a non-reversible function. Oki... A reversible function and ditto workflow ain't the same thing. ;-) I doubt if nospam can get his mind around that thought. :-( You might have notice that android addressed that comment to Floyd. So what? I was agreeing with him. Not quite. You redirected the intended comment to *nospam*, If you agreed with him your snide response would have poked at Floyd. A non-destructive workflow makes that irreversible function very reversible indeed. You are fudging word meanings. In fact you seem to be demonstrating that you too don't know the difference between a reversible function and a reversible work flow. Not at all. If you reread what I wrote below, you will see that I have a firm grasp of each of the proposed concepts in this thread. Once that working copy has had USM applied, the layers merged, and compressed into a JPEG (a destructive action) then Floyd is correct, the function can no longer be reversed. However, Floyd doesn't see the concept of the non-destructive workflow because he doesn't, or appears not to use one. He certainly isn't using what is available to those running either Lightroom or Photoshop CS6/CC/CC 2014, and ignores that some here have the ability to take advantage of a non-destructive, or "reversible" workflow because of the software tools installed on their computers. Floyd wasn't even talking about it! He was talking about different sharpening algorithms. Floyd specifically addressed high pass sharpening (HPS) in response to Alfred's query regarding USM. We ended up discussing HPS & USM and the qualities of both. I know what Floyd was talking about. -- Regards, Savageduck |
#58
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Lenses and sharpening
On 2014-09-16 08:12:12 +0000, Martin Brown
said: On 16/09/2014 05:37, John McWilliams wrote: On 9/15/14 PDT, 7:07 PM, Floyd L. Davidson wrote: Savageduck wrote: I got what Floyd was talking about when he was talking of high pass sharpening, and reversing it by applying the corresponding reverse parameter blur. However, he also stated above, "UnSharpMask is not reversible". My point addressed the fact that for some of us, that is not an entirely valid statement. IN an environment that supports a saved original copy so that all edits are non-destructive then that is true. Exactly. But the mathematics of blurring and of unsharp masking make it irreversible if you are only given just the processed image. (and not some hybrid Photoshop workflow encapsulated format) So? The fact still remains, regardless of personal opinion about Adobe, Lightroom, & Photoshop, those using that software have the ability to maintain a fully non-destructive, and reversible workflow, that includes reversing the effects of any filter including USM. That is in fact a valid statement. The USM function is not reversible. That isn't a opinion, it's a fact. For one definition of the word! This seems to have degenerated into a heated and utterly pointless semantic argument over the meaning of "reversible" that is in conflict with normal image processing and mathematical parlance. Normal imaging processing? You might have noticed that currently, Adobe produces the industry standard software in that category, and those of us who use Lightroom and Photoshop have been provided the tools to maintain a truly non-destructive and reversible workflow. A mathematical operation is reversible if a strict inverse function exists that can exactly get you back to where you started. …and if you are going to start that reverse mathematical operation from a compressed, & lossy JPEG, good luck getting back to where you started. Any operation can be made non-destructive simply by saving a copy of the original before applying the irreversible filter but that isn't very interesting. However, that isn’t quite how things work in a truly non-destructive workflow. What you have described is what at best could be called a pseudo-non-destructive workflow. Just working on a duplicate of the original isn’t the idea. To be truly non-destructive and reversible one has to be able to return to the actual file they were working on. That is going to be either a layered PSD, or TIF. The JPEG which might be produced is just a compressed, lossy snapshot of the actual, non-destructively adjusted, and uncompressed layered PSD, or TIF. It is best to consider it a version, and there is no point in even trying to rework it. Call it “version-1.jpg”. Once you are done with readjusting the layered PSD/TIF you can produce “version-2.jpg”, and still have the ability to return to the working PSD/TIF to produce a “version-3.jpg”. Some packages do support this sort of safe workflow. I know, I know. -- Regards, Savageduck |
#59
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Lenses and sharpening
Savageduck wrote:
So? The fact still remains, regardless of personal opinion about Adobe, Lightroom, & Photoshop, those using that software have the ability to maintain a fully non-destructive, and reversible workflow, that includes reversing the effects of any filter including USM. It's not a "reversible" workflow. The correct terms would be either a non-linear undo, or simply that it can be reverted. EURand if you are going to start that reverse mathematical operation from a compressed, & lossy JPEG, good luck getting back to where you started. Your workflow, even if non-destructive, will be totally unable to deal with reverting any previous editing with the exception of processes, such as sharpen (not USM), that are reversible. -- Floyd L. Davidson http://www.apaflo.com/ Ukpeagvik (Barrow, Alaska) |
#60
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Lenses and sharpening
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