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Robert Ardill

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Noise reduction workflow
« on: January 07, 2016, 03:25:39 pm »

Hi, I bought Denoise recently and in one of the articles they make the point (very strongly) that it is much better to apply noise reduction before anything else, specifically toning and sharpening.  I've verified this (for example in the Test#1 attachment) as best I could - and it does seem true that noise reduction should be applied before anything else.

If that is the case then it would seem that noise reduction must either be applied in the raw converter (LR in my case), or that any tonal adjustment and sharpening should be done after DeNoise (or equivalent) in Photoshop (or equivalent).

I would normally do most of my tonal adjustments in LR as this is part of my image selection process (after all, if the image has no shadow detail, for example, but I need the shadow detail then the image is not much good to me).  Also, LR is very good at this. So I don't really want to change my workflow ... unless, of course, LR's noise reduction is much inferior to DeNoise (et al.).

It seems to me that LRs color noise reduction is better than DeNoise's ... perhaps because it's better to do noise reduction of the raw file??

I've done a bit of luminance noise reduction testing between LR and DeNoise and I'm not at all convinced that DeNoise is better.  For example in the LR-NeDnoise attachment it seems to me that the LR noise reduction is very good, whereas the DeNoise result is quite patchy, with noise remaining in the mid-tones but removed in the shadows.  I used the presets in DeNoise, initially, but couldn't get a good result, so I adjusted the sliders to get the best result I could.  It seems to me that DeNoise tends to apply very strong noise reduction to the shadows, resulting in a flattening of the image ... and I couldn't prevent this.

I am quite new to DeNoise so I'm probably not using it as well as I could, but I have watched tutorials on how to use it and I have been quite careful.  My take at this stage is that it takes a LOT more effort than does LR ... and possibly for worse results.

At this stage I would probably tend to use LR for an initial pass, and then SELECTIVELY to use DeNoise or NoiseNinja for troublesome areas.

I wonder if any of you have quite a different experience and point of view?

FYI - the test image here was taken with a A7RII. The tonal adjustment was +5 Exposure and -80 Blacks (and nothing else). The original image was very under-exposed.

Robert

« Last Edit: January 07, 2016, 03:30:00 pm by Robert Ardill »
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Peano

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Re: Noise reduction workflow
« Reply #1 on: January 07, 2016, 06:09:57 pm »


If that is the case then it would seem that noise reduction must either be applied in the raw converter (LR in my case), or that any tonal adjustment and sharpening should be done after DeNoise (or equivalent) in Photoshop (or equivalent).

Robert

Yes, I agree with both of these. I find the ACR's noise reduction is quite good. If further NR is needed in Photoshop, I use the Imagenomic Noiseware plug-in.

TonyW

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Re: Noise reduction workflow
« Reply #2 on: January 07, 2016, 06:13:49 pm »

Hi Robert,
Interesting test and write up.  I used to use Imagenomic Noiseware for clean up of noisy TIFF or JPEG images as a plugin for Photoshop and thought it did a very good job (better than PS CS4 and 5).  I have only trialed Denoise and consequently can claim no expertise in this application.  It certainly seems to be very well thought of by many and I am sure that it is capable of excellent results when used correctly. 

For me however the main objection is that you have to drop out of a raw workflow and spawn a TIFF or JPEG when it may be possible to stay within LR with raw all the way to print output. 

So my questions are when would I use Denoise over LR, other than when I have a noisy TIFF or JPEG to deal with?   And does it give a worthwhile and measurable increase in IQ over using the LR/ACR and PS tools I already have?

Noise may be obvious when viewing on our monitors at 100% zoom in LR or ACR but image size for print would be 1/3rd of this (Canon and HP printers) where the noise may well be of little concern after moderate amounts of NR depending on image. Also downsampling the image should help alleviate troublesome noise to some degree

Hi, I bought Denoise recently and in one of the articles they make the point (very strongly) that it is much better to apply noise reduction before anything else, specifically toning and sharpening.  I've verified this (for example in the Test#1 attachment) as best I could - and it does seem true that noise reduction should be applied before anything else.
I see sharpening and noise reduction as being two parts of the whole i.e. you cannot adjust one without affecting the other and therefore should probably be tackled at the same time.  Sometimes I find myself switching back and forth between both to get the best result (or compromise), but this could just be me not having the experience of others more expert in the dark art.

Quote
If that is the case then it would seem that noise reduction must either be applied in the raw converter (LR in my case), or that any tonal adjustment and sharpening should be done after DeNoise (or equivalent) in Photoshop (or equivalent).
My feelings on the raw aspect is that generally noise reduction, sharpening (including masking to limit sharpening area) and tonal adjustments ideally should all be done within the raw environment.  Perhaps reserving specialist NR and Sharpening tools for special cases where we may have to use the likes of PS

Quote
At this stage I would probably tend to use LR for an initial pass, and then SELECTIVELY to use DeNoise or NoiseNinja for troublesome areas.
Ditto  :D, or maybe look at DxO's Prime noise reduction of which I have heard good things

Edited to clarify
« Last Edit: January 07, 2016, 06:29:16 pm by TonyW »
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Peano

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Re: Noise reduction workflow
« Reply #3 on: January 07, 2016, 08:29:57 pm »

My feelings on the raw aspect is that generally noise reduction, sharpening (including masking to limit sharpening area) and tonal adjustments ideally should all be done within the raw environment.

I agree, with the proviso that "sharpening" means only capture sharpening. Subsequent sharpening for output should be done at or near the tail end of the editing workflow.

Robert Ardill

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Re: Noise reduction workflow
« Reply #4 on: January 08, 2016, 12:59:04 pm »

Thanks Peano and Tony.

I'm fairly convinced of a couple of things at this stage:
1. Color noise reduction is best done in LR as it's fast, easy and effective.
2. Initial luminance noise reduction is also best done in LR if there is significant noise due to the tonal adjustments (if the noise reduction really is as good in LR as it is in DeNoise ...TBD).  The reason is that heavy exposure boosting clearly amplifies noise, so it's best to remove the noise before amplification ... but it's hard to see if the noise reduction is required without doing the tonal adjustments first. And, I for one don't feel like going to the trouble of doing the tonal adjustments only to undo them so that I can do the noise removal later in post-raw. 

So my questions are when would I use Denoise over LR, other than when I have a noisy TIFF or JPEG to deal with?   And does it give a worthwhile and measurable increase in IQ over using the LR/ACR and PS tools I already have?
Yes, this is something that I would like to know too.  There are additional controls in DeNoise (for example Red and Blue color sliders) that may help to minimize unnecessary noise reduction.

Noise may be obvious when viewing on our monitors at 100% zoom in LR or ACR but image size for print would be 1/3rd of this (Canon and HP printers) where the noise may well be of little concern after moderate amounts of NR depending on image. Also downsampling the image should help alleviate troublesome noise to some degree

Yes, as a an example, the test image I used, boosted by +5 and black -80 is absolutely fine for print with NO luminance noise reduction, even after applying a +2 sharpening in Focus Magic (see image ... which you can download for full size if you wish). 
I see sharpening and noise reduction as being two parts of the whole i.e. you cannot adjust one without affecting the other and therefore should probably be tackled at the same time.

It could be ... however it's easy enough to apply sharpening in LR in order to gauge the amount of noise reduction needed ... and then remove it before going to Photoshop.  And there are probably better sharpening programs than LR's sharpening, so if the final work is done in Photoshop (as in my case) then I think sharpening can be put off until later.

Robert

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Robert Ardill

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Re: Noise reduction workflow
« Reply #5 on: January 08, 2016, 01:07:02 pm »

I've done another test comparing LR to DeNoise and I have to admit that DeNoise has come out well ahead.  The attachment shows this clearly, I think (you may need to save the image and view at 100% to see the differences).  The DeNoised image has less noise, more detail and less banding. But ... I find the noise remaining with the DeNoised image not very nice .. perhaps there's a need to add a bit of grain.

Seems as though I will have to unconvince myself about doing noise reduction in LR!

So, the question is ... how to fit this in to a workflow that allows tonal adjustments in Lightroom?

Here is one possible way of doing it:
1. Develop in LR as normal
2. Create virtual copy and reset tonal adjustments
3. Open virtual copy in Photoshop and do noise removal
4. Save image into same folder as original
(or 3 & 4. Open virtual copy in Lightroom DeNoise plug-in and do noise removal)
5. Sync metadata between original (with tonal adjustments) and the de-noised image.
6. For further processing in Photoshop: Edit a copy with Lightroom Adjustments
(or 6. Export to tiff, jpeg or psd to 'burn' LR adjustments into the image)

A bit convoluted admittedly :-).  But as this sort of jiggery-pokery would only be needed for really noisy images it may not be too bad.

Perhaps someone might suggest a more elegant solution?

Robert

« Last Edit: January 08, 2016, 01:31:26 pm by Robert Ardill »
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Robert Ardill

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Re: Noise reduction workflow
« Reply #6 on: January 08, 2016, 04:43:19 pm »

Here's another test image ... but this time with only moderate noise.  In this case it isn't at all clear which is better - sort of swings and roundabouts.  What makes it more confusing is that DeNoise seems to apply some micro-contrast (you can see it on the water), but it could just be noise.

At print size there's nothing between them really - at least nothing that couldn't be adjusted very easily with a bit of micro-contrast or clarity. At 200% the DeNoise image has more shadow noise, but that could have been corrected easily enough (and it may be what is giving the appearance of micro-contrast and more detail in the pebbles (just noise, I think)).

All of which would make me think that for images that just need a little noise reduction that there's hardly any justification for going to DeNoise, especially when one considers that LR's noise reduction is non-destructive ... and also that LR noise reduction is SO much easier that DeNoise.

So at this point I would tend to use LR for noise reduction and only go to DeNoise for very noisy images.

« Last Edit: January 08, 2016, 04:47:23 pm by Robert Ardill »
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Redcrown

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Re: Noise reduction workflow
« Reply #7 on: January 09, 2016, 03:11:52 am »

I've been playing a lot with DeNoise lately too. However, I have yet to find an advantage over ACR/LR that justifies the additional workflow steps, time, and cost.

I loaded your orange box images into Photoshop, and would disagree that the DeNoise version is better. If I blow it up 300-400% and look at the flat orange area on the top I see "artifacts" that look like jpeg compression artifacts. They are not jpeg artifacts, just look like them. Dark splotches, 3 to 5 pixels wide.

I imagine these are from the sharpening in DeNoise (detail recovery, blur reduction). Your Lightroom version does not look much better, but if I take your original and process it in ACR for just noise reduction and use maybe a little stronger setting than you apparently used, I get a version that looks a little better than the DeNoise.

If I also sharpen the original in ACR, I get similar artifacts. But if I use a strong mask, the artifacts are suppressed while the fine detail is still enhanced (the white lens outline top left, the printing, etc.).

I like that DeNoise has separate settings for Overall, Shadows, and Highlights. I wish ACR/LR could do that. However, the DeNoise Shadows adjustment reaches way too far into the midtones. The Highlight adjustment is pretty good and restricted to just highlights. Also, the Detail Enhancement and Blur recovery seem to generate far too many artifacts. And DeNoise does not offer a mask on these adjustments like ACR/LR does. In your sample, the flat orange area gets hit when it does not need to, and the results are not good.

But overall, you have to pixel peep at huge magnifications to really see the differences, and even then they are minor. That's the reason I see little value in DeNoise over ACR/LR. In reduced size web images and even prints, I doubt if the differences are visible.
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Robert Ardill

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Re: Noise reduction workflow
« Reply #8 on: January 09, 2016, 05:07:08 am »

I loaded your orange box images into Photoshop, and would disagree that the DeNoise version is better. If I blow it up 300-400% and look at the flat orange area on the top I see "artifacts" that look like jpeg compression artifacts. They are not jpeg artifacts, just look like them. Dark splotches, 3 to 5 pixels wide.
I wouldn't disagree with you as I also think that DeNoise has ugly artifacts and to reduce them it's also necessary to make the noise reduction as low as is tolerable.  However the detail recovery did seem better to me in the DeNoise version.  If you're interested in trying it out on the raw file, here is a link to it: Link to boxes image

I imagine these are from the sharpening in DeNoise (detail recovery, blur reduction). Your Lightroom version does not look much better, but if I take your original and process it in ACR for just noise reduction and use maybe a little stronger setting than you apparently used, I get a version that looks a little better than the DeNoise.
Even better detail in the text and lines?

If I also sharpen the original in ACR, I get similar artifacts. But if I use a strong mask, the artifacts are suppressed while the fine detail is still enhanced (the white lens outline top left, the printing, etc.).
I prefer to leave the sharpening to Photoshop, where I usually use FocusMagic, which I have found to be excellent.  In the case of a noisy image I would probably mask out troublesome areas.  It would be nice to have a masking feature like Lightroom's in Focus Magic (or even in Photoshop)!

I like that DeNoise has separate settings for Overall, Shadows, and Highlights. I wish ACR/LR could do that. However, the DeNoise Shadows adjustment reaches way too far into the midtones. The Highlight adjustment is pretty good and restricted to just highlights. Also, the Detail Enhancement and Blur recovery seem to generate far too many artifacts. And DeNoise does not offer a mask on these adjustments like ACR/LR does. In your sample, the flat orange area gets hit when it does not need to, and the results are not good.
True. It is nice, in a way, to have the controls ... but it also makes it much more time-consuming to use.  When the end result may not necessarily be better than LR's it relegates DeNoise (for me) to images with very bad noise that I really want to use: then I would try the different options (LR, DeNoise, Photoshop, NoiseNinja ...) or combinations of these (most likely with masking), to try to get the best result that I can.

But overall, you have to pixel peep at huge magnifications to really see the differences, and even then they are minor. That's the reason I see little value in DeNoise over ACR/LR. In reduced size web images and even prints, I doubt if the differences are visible.
For sure, with low to medium noise there's nothing to it in my opinion. In general I think it's better to be very light on the noise reduction, leaving as much in as possible as any noise reduction pretty much has to also remove detail.  Viewed at print size this sort of noise is rarely visible and even less so when printed ... and it will be invisible at web sizes.  Also, a little bit of visible luminance noise doesn't always detract from the image.

I wonder if anyone knows if there is an advantage in doing noise reduction in the raw file? It certainly seems to me that color noise is more easily removed in LR than later ... but perhaps that's because LR does it better?

Robert
« Last Edit: January 09, 2016, 07:11:18 am by Robert Ardill »
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Bart_van_der_Wolf

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Re: Noise reduction workflow
« Reply #9 on: January 09, 2016, 07:36:02 am »

I wouldn't disagree with you as I also think that DeNoise has ugly artifacts and to reduce them it's also necessary to make the noise reduction as low as is tolerable.  However the detail recovery did seem better to me in the DeNoise version.

Hi Robert,

Lightroom's noise reduction is pretty decent, except for the desaturated look that seems to be the result, and I don't like that. Denoise is pretty good as well, preserves and restore color much better, and additionally offers much more intricate control also to restore the sharpness that's usually going to suffer from the denoising.

In fact that also allows a nice trick, not really sharpening as advertized, but more a high pass acutance boost, while leaving the high ISO noise unaffected/boosted.

Topaz Denoise als offers reduction of (horizontal and/or vertical) pattern noise, and the addition of monochrome grain, to reduce the plasticy look that can be the result of heavy noise reduction.

Quote
For sure, with low to medium noise there's nothing to it in my opinion. In general I think it's better to be very light on the noise reduction, leaving as much in as possible as any noise reduction pretty much has to also remove detail.  Viewed at print size this sort of noise is rarely visible and even less so when printed ... and it will be invisible at web sizes.  Also, a little bit of visible luminance noise doesn't always detract from the image.

Correct, I also usually do not use much noise reduction, unless the image is going to be blown-up a lot in output. I then use it sparingly and locally, early in the processing pipeline of events, before any sharpening.

Quote
I wonder if anyone knows if there is an advantage in doing noise reduction in the raw file? It certainly seems to me that color noise is more easily removed in LR than later ... but perhaps that's because LR does it better?

Theoretically it's better to do it in linear gamma space, and even before demosaicing, but that is also a very hard thing to do well. I believe that in current practice most Raw converter noise reduction is performed after demosaicing, and that's why tools like Topaz Denoise also perform so well.

I occasionally use a novel cutting edge noise reduction method (Total Generalized Variation Noise Reduction) also used for astronomy, but that method is very slow, requires many many settings to be brought into a kind of balance (separation between luma and chroma, noise model (depending on image content), different iterative noise removal settings for luma and chroma, (edge) detail preservation, image masking, etc.), and rarely produces much better results than Denoise.

Cheers,
Bart
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Robert Ardill

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Re: Noise reduction workflow
« Reply #10 on: January 09, 2016, 09:16:12 am »

Hi Bart ... good to hear from you again. I've been mostly painting this last year, but I've just got myself some Sony kit so I'm playing again :)

Lightroom's noise reduction is pretty decent, except for the desaturated look that seems to be the result, and I don't like that. Denoise is pretty good as well, preserves and restore color much better, and additionally offers much more intricate control also to restore the sharpness that's usually going to suffer from the denoising.

I would be interested to see your what you can achieve with the boxes image.  I expect that you are WAY more expert at DeNoise than I am, and you may be able to avoid some of the artifacts that I am getting.

In fact that also allows a nice trick, not really sharpening as advertized, but more a high pass acutance boost, while leaving the high ISO noise unaffected/boosted.

Yes, that's a useful trick.  I used to use a blur on the high-pass layer, but using DeNoise is much better.  Of course you could equally well use the Camera Raw filter.

Topaz Denoise als offers reduction of (horizontal and/or vertical) pattern noise, and the addition of monochrome grain, to reduce the plasticy look that can be the result of heavy noise reduction.

Yes, that's definitely a plus.

Theoretically it's better to do it in linear gamma space, and even before demosaicing, but that is also a very hard thing to do well. I believe that in current practice most Raw converter noise reduction is performed after demosaicing, and that's why tools like Topaz Denoise also perform so well.

Thanks for the info!

I occasionally use a novel cutting edge noise reduction method (Total Generalized Variation Noise Reduction) also used for astronomy, but that method is very slow, requires many many settings to be brought into a kind of balance (separation between luma and chroma, noise model (depending on image content), different iterative noise removal settings for luma and chroma, (edge) detail preservation, image masking, etc.), and rarely produces much better results than Denoise.

You're welcome to it :)

Robert
« Last Edit: January 09, 2016, 09:27:49 am by Robert Ardill »
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Robert Ardill

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Re: Noise reduction workflow
« Reply #11 on: January 10, 2016, 06:25:44 am »

I wonder if anyone has a really good noise mask?  The ones I've seen and used are either ones that are essentially the image desaturated inverted and blurred (which assumes that noise will primarily be in the shadows), or an edge mask to protect the edges.  The problem with the first is that ugly noise is often not necessarily in the shadows.  The second is a rather blunt effort to protect significant detail (and it assumes that the noise level isn't too close to the detail level).

I've done a little messing around to see if I could come up with something better.  The attached Photoshop action is one possibility - and the image here is an example of using it on an very noisy image.



I just used the Photoshop noise removal filter for noise removal.  To see the image at 100% you need to right-click and save it.

The basic procedure to create the mask is:
1. Make an edge mask
2. Make a noise mask by taking the difference between the (desaturated) image and a denoised copy of the (desaturated) image
3. Add the two masks to produce the final noise mask.

I would really appreciate it if any of you has a really good noise mask that you are prepared to share ... or at least the steps involved in creating it.

Robert
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