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Author Topic: Noise reduction by channel  (Read 6496 times)
Tim Lookingbill
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« Reply #20 on: January 20, 2013, 03:17:50 PM »
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They widely use deconvolution sharpening technology. So would the military on their recon imaging. Do they use NR by channel? Probably not, most of their work is B/W for the higher sensitivity of no color filters.

So I take it from your answer that means no, it wouldn't be feasible for that type of application. So what use do you see this method widely adopted?

I noticed no one else in this thread posted their own NR method to compare against. It seems most of the functionality lies in your skill set, Arthur. I know I wouldn't be able to pull those results off with my own 6MP Pentax PEFs.
« Last Edit: January 20, 2013, 03:20:26 PM by tlooknbill » Logged
Fine_Art
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« Reply #21 on: January 20, 2013, 05:33:53 PM »
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So I take it from your answer that means no, it wouldn't be feasible for that type of application. So what use do you see this method widely adopted?

I noticed no one else in this thread posted their own NR method to compare against. It seems most of the functionality lies in your skill set, Arthur. I know I wouldn't be able to pull those results off with my own 6MP Pentax PEFs.

The functions are in the software I named. All someone has to do is run them on their image. People that try to use this method from software that creates color clumps are going to have problems. The data needs to be as fine as possible.
« Last Edit: January 20, 2013, 05:37:57 PM by Fine_Art » Logged
Fine_Art
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« Reply #22 on: January 20, 2013, 07:36:48 PM »
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What works on high ISO with noise reduction works at low ISO for Sharpening.

Here is Images Plus sharpened by channel using Adaptive Richardson-Lucy on the left
Sony's IDC which makes a very good image on the right. IDC was my default converter, I know how to squeeze quality out of it very well. I used to send tiffs from it to Images Plus for sharpening.

Look at how natural the left file looks compared to the right file. In addition problems like red fringing were wiped out. This is huge. I always hated looking at files at 100% because they looked fake. Yes, I tried samples of Capture one, DxO, ACR and Raw Therapee for comparisons in the past. At 50% view Sony IDC was as good. The color was better, the detail was a bit less. Still easy to solve with AR-L.

On low ISO files the room for channel sharpening is huge. Artifacts don't build up easily.
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bjanes
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« Reply #23 on: January 21, 2013, 12:06:31 PM »
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Nikon D800 ISO3200 NR0 converted in Images plus. Note the fine random nature of the noise.

The second screenshot is with NR by channel. It gets some faint color grouping from the NR. The noise does not start to form into a pattern.

IMHO ACR with Noiseware for noise reduction provides equivalent or better results than your method and with more convenience and with color management, which your images from ImagesPlus lack. I note that your uploaded image is untagged. The colors are only generic. For most of us, color management and accurate colors are highly desirable.

With the D800, I find that NR is often unnecessary with even high ISO if one uses proper technique. Your test image is underexposed by over 1 stop as shown by Rawdigger.

Nonetheless, one often must make best use of what one has. I rendered the image into sRGB with ACR 7.3 and then applied some NR with Noiseware (I haven't felt the need to use Noiseware for some time, but it is a good plug in to have). Your conversion is on the top and there is still some speckling in the top wrapper of the wine bottle. Also the print on the calculator shows some edge artifacting and fuzziness. For my routine photography I will continue to use ACR/LR. Depending on the ISO and print size, NR beyond what is offered by LR/ACR is usually not needed with the D800. The sophisticated filters and other image processing functions in ImagesPlus are sometimes useful, but I would render the image into a TIFF with defined color space with ACR and then load the image into ImagesPlus. I think this is what Roger Clark does.

Regards,

Bill
« Last Edit: January 21, 2013, 12:18:43 PM by bjanes » Logged
Fine_Art
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« Reply #24 on: January 21, 2013, 02:43:15 PM »
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IMHO ACR with Noiseware for noise reduction provides equivalent or better results than your method and with more convenience and with color management, which your images from ImagesPlus lack. I note that your uploaded image is untagged. The colors are only generic. For most of us, color management and accurate colors are highly desirable.

With the D800, I find that NR is often unnecessary with even high ISO if one uses proper technique. Your test image is underexposed by over 1 stop as shown by Rawdigger.

Nonetheless, one often must make best use of what one has. I rendered the image into sRGB with ACR 7.3 and then applied some NR with Noiseware (I haven't felt the need to use Noiseware for some time, but it is a good plug in to have). Your conversion is on the top and there is still some speckling in the top wrapper of the wine bottle. Also the print on the calculator shows some edge artifacting and fuzziness. For my routine photography I will continue to use ACR/LR. Depending on the ISO and print size, NR beyond what is offered by LR/ACR is usually not needed with the D800. The sophisticated filters and other image processing functions in ImagesPlus are sometimes useful, but I would render the image into a TIFF with defined color space with ACR and then load the image into ImagesPlus. I think this is what Roger Clark does.

Regards,

Bill

To each their own. I think the detail looks better in mine.

Images Plus does not preserve exif.
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Fine_Art
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« Reply #25 on: January 21, 2013, 02:47:25 PM »
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Maybe someone with DxO testing software or imatest can compare the results.
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bjanes
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« Reply #26 on: January 21, 2013, 04:04:23 PM »
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Maybe someone with DxO testing software or imatest can compare the results.

I have Imatest, but problems arise since the rendered file from ImagesPlus is untagged. When you open the converted file in Photoshop you get a warning that the file is untagged as to color space. You can leave color managed or assign a profile. This is covered in this post.

I have a Nikon D3 image of a colorchecker photographed under Solux illumination (approx 4800K). I rendered the image with ImagesPlus and to gamma 2.2 and saved it untagged. I then opened it and assigned sRGB, Adobe RGB, and ProPhotoRGB. The results are shown along with  an ACR conversion. The color errors in the ImagesPlus conversions are very large. This proves my point.

Regards,

Bill
« Last Edit: January 21, 2013, 04:06:07 PM by bjanes » Logged
Fine_Art
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« Reply #27 on: January 21, 2013, 04:25:49 PM »
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Thanks, that is certainly a real issue.

What are your thoughts on the detail of the image you posted? On mine the texture of the metal wrapper on the bottle is clearly visible. On yours it is smeared out looking flat. On the background the noise is basically random on mine, on yours it is forming into color clumps. What is your analysis of that?
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bjanes
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« Reply #28 on: January 21, 2013, 05:04:04 PM »
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Thanks, that is certainly a real issue.

What are your thoughts on the detail of the image you posted? On mine the texture of the metal wrapper on the bottle is clearly visible. On yours it is smeared out looking flat. On the background the noise is basically random on mine, on yours it is forming into color clumps. What is your analysis of that?

I think that the wrapper in your image exhibits speckled artifacts that have been pointed out previously and the printing shows artifacts as I noted. Both of us are not unbiased observers, and others may comment. I am satisfied with my results and you like yours, so we are both happy.

Regards,

Bill
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Schewe
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« Reply #29 on: January 21, 2013, 05:35:49 PM »
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I have tested a new method (as far as I know) for Noise Reduction. Unless I hear its published already I will call it Arthur's method.  Wink

Not for nothing but I'm pretty sure Bruce Fraser wrote about per channel sharpening and noise reduction back in one of his early Real World Photoshop books well over a decade ago. Doing per channel noise reduction offers more flexibility than when running on composite RGB data. If you look at the Reduce Noise filter in Photoshop (with the advanced option checked) you'll see that the amount of the noise reduction can be adjusted on a per channel basis. As I recall, both Reduce Noise and Smart Sharpen (which also has per channel options) have been around for a long time and as I recall, Bruce was involved in early alpha testing of both with the engineers.

But if you are working with raw images (as apposed to film scans) I have a feeling that the ACR/LR noise reduction is pretty much leading edge and has made 3rd party noise reduction (or obscure image processing routines) a bit passe. Not reason not to keep experimenting but it's useful to know that work being done now is often (not always) built on the work of others...
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Fine_Art
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« Reply #30 on: January 21, 2013, 07:13:19 PM »
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Not for nothing but I'm pretty sure Bruce Fraser wrote about per channel sharpening and noise reduction back in one of his early Real World Photoshop books well over a decade ago. Doing per channel noise reduction offers more flexibility than when running on composite RGB data. If you look at the Reduce Noise filter in Photoshop (with the advanced option checked) you'll see that the amount of the noise reduction can be adjusted on a per channel basis. As I recall, both Reduce Noise and Smart Sharpen (which also has per channel options) have been around for a long time and as I recall, Bruce was involved in early alpha testing of both with the engineers.

But if you are working with raw images (as apposed to film scans) I have a feeling that the ACR/LR noise reduction is pretty much leading edge and has made 3rd party noise reduction (or obscure image processing routines) a bit passe. Not reason not to keep experimenting but it's useful to know that work being done now is often (not always) built on the work of others...

Thanks for the info. I'm a property developer that went to top business schools not someone in the photoshop community. I knew if it was out there someone would bring it to my attention. Per channel NR/ sharpening in whatever software does seem to be the way to go.

I seem to remember when I originally looked at the new lightroom it was $299 or something. The new $99 does make it an easy purchase for testing. Right now I think I will stay with Sony IDC, Raw Therapee and Images plus. I like the smoothing/ sharpening functions in IPlus. The flexibility of no default gamma correction is also useful.

Snow detail in a 1 of 3 shot pano. There was noise in that sky before.
http://farm9.staticflickr.com/8471/8404208734_1e82308404_o.jpg
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Fine_Art
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« Reply #31 on: January 21, 2013, 07:52:44 PM »
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I posted at Dyxum that this was done by Bruce Fraser many years back. I'm making sure credit goes back to him.
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Tim Lookingbill
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« Reply #32 on: January 21, 2013, 08:51:30 PM »
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Quote
I'm a property developer that went to top business schools not someone in the photoshop community.

Has that helped you or hindered you in your endeavors here in getting your point across?

You didn't happen to develop the neighborhood of Fairhaven in Schertz, Texas, did you? We need better developers down here in Texas who know how to build decent foundations on top of loose limestone rubble bedrock.

If you're good, get down here. The Eagle Ford Shale gas and oil production site needs a lot of homes built fast and good for all the new oilfield employees.
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bjanes
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« Reply #33 on: January 22, 2013, 03:29:50 PM »
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But if you are working with raw images (as apposed to film scans) I have a feeling that the ACR/LR noise reduction is pretty much leading edge and has made 3rd party noise reduction (or obscure image processing routines) a bit passe. Not reason not to keep experimenting but it's useful to know that work being done now is often (not always) built on the work of others...

With the OP's test image, I think that the default ACR settings do a reasonable job of noise reduction while maintaining edge contrast and fine detail. The default color settings remove almost all of the color noise and the residual luminance noise is fine grained and acceptable with the default of no luminance noise reduction. Had the image been properly exposed to the right, I think the image would have been even better. I do have Noiseware, but rarely use it with the D800e. Viewing a 36 MP image at 100% is a severe test, and the noise might not be visible in ordinary prints.

Regards,

Bill
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Fine_Art
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« Reply #34 on: January 22, 2013, 05:10:21 PM »
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Most of the credit has to go to Nikon and Sony for one hell of a camera and one hell of a sensor. With everything turned off, that test shot, despite being underexposed at ISO 3200 looks like what you would expect from ISO 400 on APS-C cameras or ISO 800 on FF of just a few years ago. Frankly the cleanup task for software was not that bad.

The ACR/LR version looks pretty good with an artificial black peppering. Color noise is controlled in the last version posted. Some fine detail is lost despite lines looking sharp. Its visible on the textured metallic wrapper.

The process I used, I'll call it Bruce's per channel NR kept fine detail by using other algorithms. The white pixels I created with deconvolution are less frequent than the black pixels of ACR. Neither will likely show up in a print. If you don't like the white ones, just run fewer cycles of deconvolution or move the slider for noise threshold. I had it at 5 standard deviations on a range of 0-10.

Attached is a screenshot of some of the smoothing and sharpening functions in Images Plus. It's a tightly coded 64bit multi-threaded app that is only 7.5MB in size. The entire installation is 8.82MB for the 4.25 version. That is pretty amazing. No code bloat here. A lot of this capability is not available in other software.

I have no association with Mike or the software other than a happy user. I get no other benefit than using it.
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bjanes
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« Reply #35 on: January 22, 2013, 07:25:19 PM »
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Attached is a screenshot of some of the smoothing and sharpening functions in Images Plus. It's a tightly coded 64bit multi-threaded app that is only 7.5MB in size. The entire installation is 8.82MB for the 4.25 version. That is pretty amazing. No code bloat here. A lot of this capability is not available in other software.
I have no association with Mike or the software other than a happy user. I get no other benefit than using it.

Your approach is interesting and would be useful when noise reduction in ACR/LR is not sufficient. The parametric editing in LR is attractive because the 36 MP D800 file expands to 200 MP in a 16 bit TIFF. How do you determine the PSF for deconvolution?

Regards,

Bill


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Fine_Art
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« Reply #36 on: January 22, 2013, 07:57:11 PM »
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Your approach is interesting and would be useful when noise reduction in ACR/LR is not sufficient. The parametric editing in LR is attractive because the 36 MP D800 file expands to 200 MP in a 16 bit TIFF. How do you determine the PSF for deconvolution?

Regards,

Bill




In the screen shot above the deconvolution controls are the top right and bottom left boxes. The top right has 3 types, Van Cittert, One step Gradient (VC with a mild smoothing in between each cycle) and Richardson-Lucy. The bottom left is all Adaptive R-L. Adaptive R-L like Adaptive USM engage only areas that meet defined parameters. These are superior to the standard versions in other software.

The PSF for all methods is defined by size (3x3, 5x5, 7x7,9x9) and type Gaussian (most common) Binomial, Box and Custom. The custom controls are lower right. You can enter values or select from the image with the mouse. If you select you can scale the values.

An example of the use of custom would be to reverse lens defects. If you take a picture of the night sky you have point sources with atmosphere effects and lens effects. You would probably deconvolve with Gaussian. If you take a picture of an artificial star or points without miles of atmosphere to contend with the errors are from your lens only. If you right click on the deformed point the custom box fills with the values of that selection. Center it. Deconvolve the image. You should get back to a point without diffraction rings. Save that "custom" for use with that lens. If you want your rings you can enter them from calculation around the central value and save that.

If you have a lens with shitty smearing in the corners you could use this process then apply it to the corners with the rest of the image masked out.

Drooling yet?
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Fine_Art
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« Reply #37 on: January 25, 2013, 12:28:10 AM »
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Crop from a single frame of tonight's moon ISO400. N/R and sharpened using this method.

« Last Edit: January 25, 2013, 05:23:43 PM by Fine_Art » Logged
jerryrock
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« Reply #38 on: January 25, 2013, 09:40:22 AM »
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How does this method compare with noise reduction features present in ACR 7.3 combined with the per channel noise reduction available in Photoshop CS6?
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Gerald J Skrocki
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« Reply #39 on: January 25, 2013, 12:59:34 PM »
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Bob showed a comparison. I'm sure he is a very skilled user of ACR.
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