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#751
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 2014.10.06, 19:44 , Eric Stevens wrote:
On Mon, 06 Oct 2014 17:42:50 -0400, Alan Browne wrote: On 2014.10.06, 17:27 , Eric Stevens wrote: On Sun, 05 Oct 2014 22:37:46 -0400, Alan Browne wrote: On 2014.10.05, 20:55 , PeterN wrote: On 10/5/2014 6:57 PM, Alan Browne wrote: On 2014.10.05, 14:42 , PeterN wrote: We went through all this some many months ago. I demonstrated clearly that the amount of 'loss' was negligible in practical terms. I would use the terem "color change." anstead of loss. Any change is a quality loss. Whether that is colour difference, tone, brightness, sharpness ... whatever, it's a loss. Then you are using a different definition of quality. Not at all. A non lossy process would have: RGB-A -- X-format -- RGB-B with RGB-A identical to RGB-B But - the fact is that with Lab RGB-A -- Lab -- RGB-B RGB-A =/= RGB-B, therefore there was quality loss. But hang on: we do accept a certain degree of quality loss as part of the normal process of editing. It doesn't take much manipulation to turn a smooth histogram into something like http://pe-images.s3.amazonaws.com/ba.../fix-white.gif Push things a bit harder and you can get http://www.snoopy.me.uk/misc/365proj...gram/comb3.jpg or even https://aperture64.files.wordpress.c...09/combing.gif The 'issue' refers to the questions: "If I take my JPG and throw it into LAB ('cause I want to do something easier done there) and then throw it back, is there a loss? Is it important?" 1. Yes. 2. Negligible. So in a "normal process of editing" where one goes from a high quality image (raw) to the Adobe "editing space" format and then save as a: PSD: no loss (other than editing effects) TIFF: no loss (other than editing effects) JPG: lossy But if one went to Lab space and back along the way, then it will always be lossy even if nothing was done in Lab space. True, but as I found in my experiments (as described again, below) the loss on conversion is close to zero. The argument is not whether or not there is any loss in going through Lab space but whether or not the loss is significant. nospam seems to equate even the smallest loss arising from Lab conversion as significant but he forgets that the fact that he has loaded the image into an editor is going to wreak considerably more damage to the original image. That's why I think he is talking nondense when he advocates not using Lab so as to avoid damage. We're in violent agreement ... (in all respects ;-) ). OTOH the "need" for working in Lab space is rare (for me), but when I want (especially) to do something creative in colour exchange, it's the best. That's rare though. -- Among Broad Outlines, conception is far more pleasurable than “carrying [the children] to fruition.” Sadly, “there’s a high infant mortality rate among Broad Outlines—they often fall prey to Nonstarters.” "Bestiary of Intelligence Writing" - CIA |
#752
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 10/7/2014 3:52 PM, PeterN wrote:
....large snip.... Thanks, What you and Dr. Brown say makes sense. From a photo standpoint I will continue to keep LAB in my workflow, while trying not to overdue it. There is an interesting discussion on using LAB to control color saturation at: http://www.dgrin.com/showthread.php?t=18308 though it may have been posted before. I'd tend to think of Lab mode as just another tool to work with as needed. The more tools the better, but do take the time to learn the range and limitations of the stuff in your tool box. Anyway, sticking my neck out (for what little it may be worth), I pulled the squirrel photo out from the above "..dgrin.com/.. " thread and had a go with it in Lab space. I've posted the before and my after in my photobucket if anyone may care. http://s1351.photobucket.com/user/Ed...ry/Lab%20tests http://tinyurl.com/kyrt87u I'm guessing similar results could be had in RGB space. == Later... Ron C -- |
#753
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 10/8/2014 10:51 PM, Ron C wrote:
On 10/7/2014 3:52 PM, PeterN wrote: ....large snip.... Thanks, What you and Dr. Brown say makes sense. From a photo standpoint I will continue to keep LAB in my workflow, while trying not to overdue it. There is an interesting discussion on using LAB to control color saturation at: http://www.dgrin.com/showthread.php?t=18308 though it may have been posted before. I'd tend to think of Lab mode as just another tool to work with as needed. The more tools the better, but do take the time to learn the range and limitations of the stuff in your tool box. Anyway, sticking my neck out (for what little it may be worth), I pulled the squirrel photo out from the above "..dgrin.com/.. " thread and had a go with it in Lab space. I've posted the before and my after in my photobucket if anyone may care. http://s1351.photobucket.com/user/Ed...ry/Lab%20tests http://tinyurl.com/kyrt87u I'm guessing similar results could be had in RGB space. == Later... Ron C LAB is indeed another tool that can be useful. Here is an example of saturation differences. http://blog.epicedits.com/2007/12/20/photoshop-technique-lab-saturation-adjustments/ Yet when -- PeterN |
#754
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 2014-10-09 15:47:57 +0000, PeterN said:
On 10/8/2014 10:51 PM, Ron C wrote: On 10/7/2014 3:52 PM, PeterN wrote: ....large snip.... Thanks, What you and Dr. Brown say makes sense. From a photo standpoint I will continue to keep LAB in my workflow, while trying not to overdue it. There is an interesting discussion on using LAB to control color saturation at: http://www.dgrin.com/showthread.php?t=18308 though it may have been posted before. I'd tend to think of Lab mode as just another tool to work with as needed. The more tools the better, but do take the time to learn the range and limitations of the stuff in your tool box. Anyway, sticking my neck out (for what little it may be worth), I pulled the squirrel photo out from the above "..dgrin.com/.. " thread and had a go with it in Lab space. I've posted the before and my after in my photobucket if anyone may care. http://s1351.photobucket.com/user/Ed...ry/Lab%20tests http://tinyurl.com/kyrt87u I'm guessing similar results could be had in RGB space. == Later... Ron C LAB is indeed another tool that can be useful. Here is an example of saturation differences. http://blog.epicedits.com/2007/12/20/photoshop-technique-lab-saturation-adjustments/ Yet when That is a 7+ year old article, much has changed both with photoshop, ACR and some very useful plug-ins which do a better job than resorting to LAB. So, regardless of whether a LAB in & out cycle is lossy or not, the question remains; for other than some arcane specialized purpose, why bother with LAB? There are very good plug-ins from NIK, OnOne, AlienSkin, Intensify Pro (for Mac users only), and even the dreaded Topaz. For the saturation adjustment try exploring NIK Viveza 2. I am not even going to address sharpening in LAB given the current proficiency of the tools we have available without LAB, and the obvious polarizing stance of folks in this room. As for dealing with the haze issue look no further than some of the tools available in NIK Color Efex Pro 4, or even better embrace the haze and make if a part of the image. There isn't much point in discussing the capabilities of Intensify Pro here for our Windows users, other than to say it makes an interesting alternative for the Mac user to some of the other more costly plug-ins for $24.99. -- Regards, Savageduck |
#755
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 2014-10-09 16:26:20 +0000, Savageduck said:
On 2014-10-09 15:47:57 +0000, PeterN said: On 10/8/2014 10:51 PM, Ron C wrote: On 10/7/2014 3:52 PM, PeterN wrote: ....large snip.... Thanks, What you and Dr. Brown say makes sense. From a photo standpoint I will continue to keep LAB in my workflow, while trying not to overdue it. There is an interesting discussion on using LAB to control color saturation at: http://www.dgrin.com/showthread.php?t=18308 though it may have been posted before. I'd tend to think of Lab mode as just another tool to work with as needed. The more tools the better, but do take the time to learn the range and limitations of the stuff in your tool box. Anyway, sticking my neck out (for what little it may be worth), I pulled the squirrel photo out from the above "..dgrin.com/.. " thread and had a go with it in Lab space. I've posted the before and my after in my photobucket if anyone may care. http://s1351.photobucket.com/user/Ed...ry/Lab%20tests http://tinyurl.com/kyrt87u I'm guessing similar results could be had in RGB space. == Later... Ron C LAB is indeed another tool that can be useful. Here is an example of saturation differences. http://blog.epicedits.com/2007/12/20/photoshop-technique-lab-saturation-adjustments/ Yet when That is a 7+ year old article, much has changed both with photoshop, ACR and some very useful plug-ins which do a better job than resorting to LAB. So, regardless of whether a LAB in & out cycle is lossy or not, the question remains; for other than some arcane specialized purpose, why bother with LAB? There are very good plug-ins from NIK, OnOne, AlienSkin, Intensify Pro (for Mac users only), and even the dreaded Topaz. For the saturation adjustment try exploring NIK Viveza 2. I am not even going to address sharpening in LAB given the current proficiency of the tools we have available without LAB, and the obvious polarizing stance of folks in this room. As for dealing with the haze issue look no further than some of the tools available in NIK Color Efex Pro 4, or even better embrace the haze and make if a part of the image. There isn't much point in discussing the capabilities of Intensify Pro here for our Windows users, other than to say it makes an interesting alternative for the Mac user to some of the other more costly plug-ins for $24.99. Oops! that was for the lesser Intensify, Intensify Pro is $59.99. -- Regards, Savageduck |
#756
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 10/9/2014 12:26 PM, Savageduck wrote:
On 2014-10-09 15:47:57 +0000, PeterN said: On 10/8/2014 10:51 PM, Ron C wrote: On 10/7/2014 3:52 PM, PeterN wrote: ....large snip.... Thanks, What you and Dr. Brown say makes sense. From a photo standpoint I will continue to keep LAB in my workflow, while trying not to overdue it. There is an interesting discussion on using LAB to control color saturation at: http://www.dgrin.com/showthread.php?t=18308 though it may have been posted before. I'd tend to think of Lab mode as just another tool to work with as needed. The more tools the better, but do take the time to learn the range and limitations of the stuff in your tool box. Anyway, sticking my neck out (for what little it may be worth), I pulled the squirrel photo out from the above "..dgrin.com/.. " thread and had a go with it in Lab space. I've posted the before and my after in my photobucket if anyone may care. http://s1351.photobucket.com/user/Ed...ry/Lab%20tests http://tinyurl.com/kyrt87u I'm guessing similar results could be had in RGB space. == Later... Ron C LAB is indeed another tool that can be useful. Here is an example of saturation differences. http://blog.epicedits.com/2007/12/20/photoshop-technique-lab-saturation-adjustments/ Yet when That is a 7+ year old article, much has changed both with photoshop, ACR and some very useful plug-ins which do a better job than resorting to LAB. So, regardless of whether a LAB in & out cycle is lossy or not, the question remains; for other than some arcane specialized purpose, why bother with LAB? There are very good plug-ins from NIK, OnOne, AlienSkin, Intensify Pro (for Mac users only), and even the dreaded Topaz. For the saturation adjustment try exploring NIK Viveza 2. I am not even going to address sharpening in LAB given the current proficiency of the tools we have available without LAB, and the obvious polarizing stance of folks in this room. As for dealing with the haze issue look no further than some of the tools available in NIK Color Efex Pro 4, or even better embrace the haze and make if a part of the image. There isn't much point in discussing the capabilities of Intensify Pro here for our Windows users, other than to say it makes an interesting alternative for the Mac user to some of the other more costly plug-ins for $24.99. The fact is that very little can be done in any plug-in that can't be done in PS. Almost anything can be done in both RGB & LAB. LAB is a lot easie, and faster for some processes. that gives more flexability, which is a good thing. Getting into a tool war, is meaningless, unless there is a reasonable accurate description of what eah plug-in does. Habing said that, I am annoyed that the oil paint filter was removed from CC 2014. -- PeterN |
#757
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 2014-10-09 17:49:40 +0000, PeterN said:
On 10/9/2014 12:26 PM, Savageduck wrote: On 2014-10-09 15:47:57 +0000, PeterN said: On 10/8/2014 10:51 PM, Ron C wrote: On 10/7/2014 3:52 PM, PeterN wrote: ....large snip.... Thanks, What you and Dr. Brown say makes sense. From a photo standpoint I will continue to keep LAB in my workflow, while trying not to overdue it. There is an interesting discussion on using LAB to control color saturation at: http://www.dgrin.com/showthread.php?t=18308 though it may have been posted before. I'd tend to think of Lab mode as just another tool to work with as needed. The more tools the better, but do take the time to learn the range and limitations of the stuff in your tool box. Anyway, sticking my neck out (for what little it may be worth), I pulled the squirrel photo out from the above "..dgrin.com/.. " thread and had a go with it in Lab space. I've posted the before and my after in my photobucket if anyone may care. http://s1351.photobucket.com/user/Ed...ry/Lab%20tests http://tinyurl.com/kyrt87u I'm guessing similar results could be had in RGB space. == Later... Ron C LAB is indeed another tool that can be useful. Here is an example of saturation differences. http://blog.epicedits.com/2007/12/20/photoshop-technique-lab-saturation-adjustments/ Yet when That is a 7+ year old article, much has changed both with photoshop, ACR and some very useful plug-ins which do a better job than resorting to LAB. So, regardless of whether a LAB in & out cycle is lossy or not, the question remains; for other than some arcane specialized purpose, why bother with LAB? There are very good plug-ins from NIK, OnOne, AlienSkin, Intensify Pro (for Mac users only), and even the dreaded Topaz. For the saturation adjustment try exploring NIK Viveza 2. I am not even going to address sharpening in LAB given the current proficiency of the tools we have available without LAB, and the obvious polarizing stance of folks in this room. As for dealing with the haze issue look no further than some of the tools available in NIK Color Efex Pro 4, or even better embrace the haze and make if a part of the image. There isn't much point in discussing the capabilities of Intensify Pro here for our Windows users, other than to say it makes an interesting alternative for the Mac user to some of the other more costly plug-ins for $24.99. The fact is that very little can be done in any plug-in that can't be done in PS. Almost anything can be done in both RGB & LAB. LAB is a lot easie, and faster for some processes. that gives more flexability, which is a good thing. Getting into a tool war, is meaningless, unless there is a reasonable accurate description of what eah plug-in does. Do the research, & experimenting, you have the plug-ins. Habing said that, I am annoyed that the oil paint filter was removed from CC 2014. to the best of my recollection the "Oil Paint" filter and one other were add-ons back with CS5. I see that it isn't there in CC (2014). So I checked with the "Filter Gallery" and I see that will only be available in 8-Bit mode, and "Oil Paint" is absent from that. So, for now if you want to use the "Oil Paint" filter you will have to uses PS CC or CS6. That said I am sure that with some digging about it can be located and installed. Perhaps Adobe support might be able to help. -- Regards, Savageduck |
#758
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 10/9/14 PDT, 11:55 AM, Savageduck wrote:
On 2014-10-09 17:49:40 +0000, PeterN said: On 10/9/2014 12:26 PM, Savageduck wrote: The fact is that very little can be done in any plug-in that can't be done in PS. Almost anything can be done in both RGB & LAB. LAB is a lot easie, and faster for some processes. that gives more flexability, which is a good thing. Getting into a tool war, is meaningless, unless there is a reasonable accurate description of what eah plug-in does. Do the research, & experimenting, you have the plug-ins. Habing said that, I am annoyed that the oil paint filter was removed from CC 2014. to the best of my recollection the "Oil Paint" filter and one other were add-ons back with CS5. I see that it isn't there in CC (2014). So I checked with the "Filter Gallery" and I see that will only be available in 8-Bit mode, and "Oil Paint" is absent from that. So, for now if you want to use the "Oil Paint" filter you will have to uses PS CC or CS6. That said I am sure that with some digging about it can be located and installed. Perhaps Adobe support might be able to help. If you really want to paint, get StudioArtist v. 4. Amazing program. Free trial. And, IIRC, there used to be actions you could download (or make yourself) that'd do painterly things. |
#759
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 2014-10-10 03:26:22 +0000, John McWilliams said:
On 10/9/14 PDT, 11:55 AM, Savageduck wrote: On 2014-10-09 17:49:40 +0000, PeterN said: On 10/9/2014 12:26 PM, Savageduck wrote: The fact is that very little can be done in any plug-in that can't be done in PS. Almost anything can be done in both RGB & LAB. LAB is a lot easie, and faster for some processes. that gives more flexability, which is a good thing. Getting into a tool war, is meaningless, unless there is a reasonable accurate description of what eah plug-in does. Do the research, & experimenting, you have the plug-ins. Habing said that, I am annoyed that the oil paint filter was removed from CC 2014. to the best of my recollection the "Oil Paint" filter and one other were add-ons back with CS5. I see that it isn't there in CC (2014). So I checked with the "Filter Gallery" and I see that will only be available in 8-Bit mode, and "Oil Paint" is absent from that. So, for now if you want to use the "Oil Paint" filter you will have to uses PS CC or CS6. That said I am sure that with some digging about it can be located and installed. Perhaps Adobe support might be able to help. If you really want to paint, get StudioArtist v. 4. Amazing program. Free trial. Not really for me, my painting skills are questionable at best, so I am not going to spend $300 on that type of program. Peter is the one who misses the "Oil Paint" filter in PS CC (2014). However, he has both CS6 & PS CC where it still exists and functions as designed. Also the PS "Filter Gallery" gives the artist access to a whole bunch of brushes, styles and effects. My less ambitious painting skills are catered to with stuff bundled with my Wacom Intuous 4, Corel Painter Sketch Pad, & Sketchbook Express. Then with my iPad I have the very powerful ArtStudio. And, IIRC, there used to be actions you could download (or make yourself) that'd do painterly things. -- Regards, Savageduck |
#760
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Is RGB to Lab lossy? - was( Lenses and sharpening)
On 10/9/2014 11:26 PM, John McWilliams wrote:
On 10/9/14 PDT, 11:55 AM, Savageduck wrote: On 2014-10-09 17:49:40 +0000, PeterN said: On 10/9/2014 12:26 PM, Savageduck wrote: The fact is that very little can be done in any plug-in that can't be done in PS. Almost anything can be done in both RGB & LAB. LAB is a lot easie, and faster for some processes. that gives more flexability, which is a good thing. Getting into a tool war, is meaningless, unless there is a reasonable accurate description of what eah plug-in does. Do the research, & experimenting, you have the plug-ins. Habing said that, I am annoyed that the oil paint filter was removed from CC 2014. to the best of my recollection the "Oil Paint" filter and one other were add-ons back with CS5. I see that it isn't there in CC (2014). So I checked with the "Filter Gallery" and I see that will only be available in 8-Bit mode, and "Oil Paint" is absent from that. So, for now if you want to use the "Oil Paint" filter you will have to uses PS CC or CS6. That said I am sure that with some digging about it can be located and installed. Perhaps Adobe support might be able to help. If you really want to paint, get StudioArtist v. 4. Amazing program. Free trial. And, IIRC, there used to be actions you could download (or make yourself) that'd do painterly things. Thanks for the information. I have used Corel Painter XI, but there are a lot compatibility issues. My workaround is to convert my file to tiff, wich can be a PITA. I am currently testing a new Topaz Impressions, and keeping CS6 installd. -- PeterN |
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