Eliminating noise in HDR tonemapped images...

So there are occasional gripes and questions regarding how to eliminate grain and noise when tone mapping an HDR dataset.

THere are, of course, plenty of techniques but most often the response is something to the effect that one should use a raw converter, use the noise reduction in that conversion to handle the noise and then merge to HDR.

Here's an alternative that is much more effective, mostly because the technique relies upon the notoriously awesome and confounding application known as Zero Noise.

One of the features of Zero Noise is the ability to output a bracketed set of 16 bit TIFFs with the desired EV spacing. Why is this even remotely interesting? Because what Zero Noise is capable of doing is taking your raw bracketed data, combining the best, noise free pixels across the exposure range and then delivering to you a bracket, ready for merging and tone mapping, that IS NOISE FREE. This is nothing new, I just have not had the time to get around to addressing the often vexing issue of noise and artifact in HDR tone mapping.

I will post an example of what I mean once I get a chance to pick and process an easy to appreciate image set.

People, this is good stuff. For those of you who do not know what Zero Noise is, google it. It is a windows application written by forum member "_GUI_" and it is pretty fantastic. It is utilitarian and requires some patience and work to understand what is going on and how to get the application to do what you want. I wrote a mini-tutorial about the basics a while ago:

https://photography-on-the.net/forum/showthre​ad.php?t=775795

I run it on my mac in Parallels (Win XP and Linux) as well as Wine.

Stay tuned....

Kirk

Kirk,

Great suggestion, as long as you are working with three images. What about an AEB set that has more than 3 frames? I spent days playing with Zero Noise, which I'm sure you remember because I was sending you PMs like crazy. LOL

Eventually, I gave up on it due to the 3 image limit. A lot of my HDR is done with 5 or 7 frames, which makes ZN useless to me. With my real estate interiors, the DR is oftern -3 to +3, or -4 to +4. There is no way to capture that in 3 frames and have enough data to get good results.

If there is something I am missing about how to work with more that e images, I have yet to find a clear and easily understandable guide to do so. If you know of one, PLEASE share. I would love to use that program but the 3 image limitation is more frustrating than the time it takes the program to go from step 1 to completion.

Please don't get me wrong, the program has a lot of potential, but it really would be better if it could take more than 3 images. Or, if there was a user guide to explain how to use it.

Oh yeah, and the file name length thing....that is really annoying. You have to rename all your images with one letter names, move them all to a folder directly off the C drive. This is just unnecessary and should be fixed.

Again, the program has potential, but all the steps and time it takes to get your images is just not worth it when you can quickly run a NR and then run the HDR software.

I'll make sure I try an image set with more than three input images and see what I get.

Kirk

Here is an interior that I have done much testing with, this time blending 4 exposures (not from ZN, but processed elsewhere) with tufuse:

http://www.tawbaware.c​om/tufuse.htm

Kirk

Any time you go over 3 images you get a big red X across the entire image. If that can be removed, then it would be good to go. But, even the creator has emailed me back and told me that the red X will be there if you use more than 3 images. That just doesn't make sense to me, but that is straight from the creator.

If you are getting a different result, I would like to know how.

Thanks!

TGrundvig wrote in post #13248808
Any time you go over 3 images you get a big red X across the entire image. If that can be removed, then it would be good to go.

If you demonstrate me you really NEED ('need' is different from 'want', or 'think you need') more than 3 source images, I promise to send you a watermark free copy of ZN. With a {0,+3,+6} bracketing, a typical 9 stops camera can capture scenes with 15 stops of DR (if you have a Pentax K5 or Nikon D7000 this figure will rise up to 17 stops, nearly sick). On the other hand the Linux version Kirk is using on his Mac is watermark free and about 3-4 times faster than the Windows version.

I think ZN is a very good tool, not only to use it, but to learn about what HDR in a digital camera is about. One of the things you can learn with it is why bracketing is actually needed, and also learn that more images doesn't mean better HDR output.

Here is a great tutorial from a friend of mine that mimics exactly what ZN does, but without needing any software than PS: Yet another method to reduce noise with two exposures. It is only suited to merge 2 images, but again it's an effective learning tool to understand the insights of HDR capture: noise.

For those interested, I didn't give up the development of ZN and its DNG version, just put it to sleep for a while since I have some other priorities now. Specially enjoying mirrorless cameras and a different kind of photography approach, using cheap vintage manual lenses for street shooting:

I tried Zero Noise for quite awhule as well, and when it works it works well, but it does amount to more work to get to the results. After awhile you have to ask how much work you want to put into something before your putting more work in than getting results.
I eventually reached that point, but found it very promising, and hope you put some more work into it to make it easier to use.

Hi....I´ve been wanting to try Zero noise for along time to see if it works as good on landscapes as it seems to on interiors, but I´ve never managed to get it to work. This little program seems to have been designed to punish the wicked ( or the stupid ) My computer skills are next to nothing so I would be very greatful if you could post an idiot proof tutorial on how to get both Zero noise and Dcraw installed on windows vista 32 bit.
The first time I tried last year I could get version 0.9 but not 1.1 to run but it always crashed at the same point. Then just last week I was trying again but this time I couldn´t even get ether Dcraw or Zero noise to install. Dcraw just flashed up for a second and disapeared, I have Rawtherapee installed I dont know if that has any thing to do with it. Then Zero noise told me I didn´t have a MSSTDFMT.DLL. on my computer, I googled what this was and since I don´t have any problems with any other programs and with my skills didn´t want to start with .DLL. files so I just gave up yet again.
Also there seems to be a version 1.1 cannedheatspecialediti​on ¿ what does this do ? ( maybe it plays great music while you are waiting for your blended TIFF ) jajaja

Mark

MGH wrote in post #13250920
Hi....I´ve been wanting to try Zero noise for along time to see if it works as good on landscapes as it seems to on interiors, but I´ve never managed to get it to work. This little program seems to have been designed to punish the wicked ( or the stupid ) My computer skills are next to nothing so I would be very greatful if you could post an idiot proof tutorial on how to get both Zero noise and Dcraw installed on windows vista 32 bit.
The first time I tried last year I could get version 0.9 but not 1.1 to run but it always crashed at the same point. Then just last week I was trying again but this time I couldn´t even get ether Dcraw or Zero noise to install. Dcraw just flashed up for a second and disapeared, I have Rawtherapee installed I dont know if that has any thing to do with it. Then Zero noise told me I didn´t have a MSSTDFMT.DLL. on my computer, I googled what this was and since I don´t have any problems with any other programs and with my skills didn´t want to start with .DLL. files so I just gave up yet again.
Also there seems to be a version 1.1 cannedheatspecialediti​on ¿ what does this do ? ( maybe it plays great music while you are waiting for your blended TIFF ) jajaja

DCRAW cannot be installed, it's a .exe file ready to work from the command line. The flash you got is because you double clicked on it, but... why did you double clicked on it? you just need to create a folder called c:\dcraw\ and copy dcraw.exe on it.

The MSSTDFMT.DLL library is missing in some Windows, I have no idea why. You just need to install it like any other library.

All is explained in the ZERO NOISE TUTORIAL.

Regards

GUI, I shoot interiors for a living. When it comes to getting the entire DR of an interior with clear windows views, the dynamic range is usually -3 to +3, or -4 to +4. I tried to take just three images from the AEB set and run them through ZN, but the results were very poor. I shoot with a Canon 1Ds Mk II, so I know the DR of the camera is fine. When I shoot a 5 or 7 frame AEB I get much better results than when I shoot with out 3 images.

I shoot over 400 properties a year so this is not something I do here or there or some of the time, this is my full time job. I took several different options of only 3 images and none of them gave usable results from ZN. When I used the -4, 0, and +4 images I got a lot of noise from ZN on the areas that did not have clean data from those three images. When I tried the -3, 0, and +3 images I got less noise, but the interiors were too dark in the final output images and there was still some areas that did not come out well.

Like I said, I do this full time and I have never seen a program produce good results with only 3 images. Blown out windows are unacceptable to my clients that want window views. This is where the 3 images just don't get the job done. It is not just ZN, it is every HDR program out there. More images means more clean data for the program. That is just common knowledge. The more clean data you load into the program, the less data the program has to make up. The results are always better with what I do with more images. Go read through the real estate and architecture thread, every single professional that shoots interiors uses at least 5 images. That is because it produces better results than just 3 images on really high dynamic range scenes. Go look up Michael James interior photography and you will see he uses 9 images. He too says, from personal experience, that 3 images will never get the job done for high end interior work.

If was shooting landscapes, or some other type of photography, then I'm sure your program would be just fine. But 3 images is not enough for the dynamic ranges I have to deal with in my line of photography.

Thanks Guillermo for your help and info. I mist that about the .DLL. library at the end fo the tutorial.
Una cosa mas, cuando se pone esto sobre el version 1.1 " a continuación sustituir su ejecutable por el de la actualización." ¿ que es exactament que tienes que hacer ?

Gracias y un saludo desde Malaga

TGrundvig wrote in post #13251376
GUI, I shoot interiors for a living. When it comes to getting the entire DR of an interior with clear windows views, the dynamic range is usually -3 to +3, or -4 to +4. I tried to take just three images from the AEB set and run them through ZN, but the results were very poor. I shoot with a Canon 1Ds Mk II, so I know the DR of the camera is fine. When I shoot a 5 or 7 frame AEB I get much better results than when I shoot with out 3 images.

Hi TGrundvig, since you don't show examples of your problems when using 3 images, I cannot decipher what was wrong. I don't make a living on photography, but I shoot interiors from time to time for fun and teach workshops about HDR, and never had a real need for more than 3 shots.

It's all about simple maths. If your camera can capture C stops of DR, and you shoot N times with M stops of spacing, assuming your blend (either manual or via software) is optimum you will be able to capture a DR of:

DR = C + (N - 1) * M

Putting real world numbers to that, if your camera can capture 9 stops (newer cameras, unfortunately non Canon, reach 11 stops), and you shoot 3 times spacing 3 stops, you get:

DR = 9 + (3 - 1) * 3 = 15 stops

Let's compare those 15 stops with some typical real world situations. I like to calculate the DR of the scenes (I am not talking about doing some in situ spot metering, but mathematically calculate the DR once at home), just to have an idea of what I can expect in the different standard scenarios. For example I know a typical tungsten lit room with some window open outside to a sunny day means about 12-13 stops.

Just some examples (please ignore how well/badly they have been tonemapped, you are surely much better than me at doing this. I just want to show that the capture was flawless, providing noiseless shadows and non-clipped highlights without needing more shots):

SCENE 1:

HTTP response: NOT FOUND | MIME changed to 'image/png'

HTTP response: NOT FOUND | MIME changed to 'image/jpeg'

MGH wrote in post #13251547
Una cosa mas, cuando se pone esto sobre el version 1.1 " a continuación sustituir su ejecutable por el de la actualización." ¿ que es exactament que tienes que hacer ?

Tío, si sabes español, ya te vale . No seas perro y léete el tutorial anda. Allí lo explica TODO. Lo de la versión 1.1 se explica en un .txt que viene en el zip con la versión.

Salu2!

When I get a chance, I will run the images again and show you the final images. Since they were not usable, I did not save them. I'll have to do it over the weekend.

Maybe I just need to shoot the scene differently, if that is the case then I will be happy if I can use ZN. But with all the images I tried to use, I just could not get good results.

Thanks for your time and input, I really appreciate it.

TGrundvig wrote in post #13251866
When I get a chance, I will run the images again and show you the final images.

If you upload the RAW files somewhere, I'd have no problem to process them and calculate the DR of the scene, to find out if really more than 3 shots were needed.

Finally a scene with more than 16 stops of DR. It's a dark WC in Botswana (no lighting at all), with a little window where the sunlight was impacting: