Enfuse for exposure blending and noise removal

[panoguy]

Hi Folks,

I'm a big believer in bracketing (AEB and others) and although I've made and used HDR files for 8 years now, I really prefer the "natural look" of exposures blended with a new, open-source technology called "Enfuse." Rather than bore with the details, it is a blender that uses image "fusion" to pick the best exposed or focused pixels among a stack of brackets, but it also considers neighboring pixels while discounting noise.

So, what can it do?
- Exposure blending; without halos or "unnatural" contrast or grunge.
- Noise reduction; by combining multiple high-ISO shots of the same exposure
- Focus blending; by taking the best focused areas from multiple shallow DOF shots

Although it exists as open-source code, many friendly UIs exist (for free or for cheap) to make the process as easy as possible for anyone. Many of these UIs also provide automatic alignment for hand-held brackets!

* The best UI, without doubt, is the MacOS-only Bracketeer. ($30, fast, easy, big preview, auto-alignment)

* Next best is TuFuse Pro for Windows. (Beta, so free for now - lots of options, including focus-blending and auto-alignment)

* Also available is EnfuseGUI for Windows. (Freeware, minimal UI, can auto-align)

If you're on Linux, you can probably build and package it youself. ;-)


Here are some examples from the March 15th Toronto Pentaxians meetup of the exposure blending (doorway) and noise reduction (my lens). All auto-aligned and Enfused using Bracketeer on an iMac.

Three AEB exposures, handheld (auto-aligned), at 10mm.


Enfused into a single image with realistic (IMHO) detail in the floor, walls, and outside the door. No halos or weird noise here!

(**Note that auto-alignment of handheld fisheye images is extremely difficult, so there is some softness in this example at the edges.)

Noise reduction by Enfusing two identically exposed ISO 3200 handheld shots without any NR done in-camera or in processing (shown side-by-side in Photoshop):



Let me know if you have any questions, but download the apps above and try them out!

-Mark

[Gooshin]

incredible!

[k100d]

awesome work mark!

[farfisa]

Very cool!

I wondered what the hell you were talking about in the meetup thread

This would really come in handy for interiors. I did some stuff like this manually last week and it was a lot of work and didn't even work this well!

[panoguy]

Some notes: I used a K20D for these examples, and the example of two noisy shots blended together was shot in a dark bar with vizjerei's 77 Ltd a bit too close to the table (and I was against the wall, so its inside the minimum focus distance).

Now that I look at the noise example, there tends to be more visible "blue" noise in the source image, and the noise tends to be lighter than the rest of the pixels, so that must be why the Enfused result is warmer and darker.

[Gooshin]

Originally Posted by panoguy

Some notes: I used a K20D for these examples, and the example of two noisy shots blended together was shot in a dark bar with vizjerei's 77 Ltd a bit too close to the table (and I was against the wall, so its inside the minimum focus distance).

Now that I look at the noise example, there tends to be more visible "blue" noise in the source image, and the noise tends to be lighter than the rest of the pixels, so that must be why the Enfused result is warmer and darker.

dude, if soemone said that the 2nd shot was ISO3200 i would laugh in their face!

that is truly amazing.

[panoguy]

Originally Posted by Gooshin

dude, if soemone said that the 2nd shot was ISO3200 i would laugh in their face!

No kidding - and 14.6 MP of it, too! I'll put the originals up somewhere so the EXIF-peepers can get with the program, too.

-Mark

[RawheaD]

I've thought about stacking multiple shots and Enfusing them to reduce high ISO noise. The same principle is commonly used in astrophotography.

The problem is, if you're shooting still life that doesn't move––which is a prerequisite for this method––then there's no point in shooting ISO3200. Why not just shoot ISO800 at 4x the exposure?

I guess if you don't have a tripod and you *have* to shoot handheld *AND* you're shooting in such a dark place so that ISO3200 @ 1/15 is the absolute minimum required, then this technique will come in handy.

Not to diss your experiment; it's a very cool concept in theory :-) Just that, I can't think of practical applications for it.

[panoguy]

Originally Posted by RawheaD

Not to diss your experiment; it's a very cool concept in theory :-) Just that, I can't think of practical applications for it.

Uh, how about when you meet up with fellow pentaxians in a very dark bar, borrow a nice lens and try it out by shooting something on the tabletop, handheld? There are many practical applications, but that varies based on experience and imagination.

JPEG versions (without any NR) of the originals can be downloaded from here: http://www.mab3d.com/temp/HISO_enfusetestimages.zip As you can see, they were not just ISO 3200, but 1/20 at f1.8... and I really didn't feel like popping up the flash or lugging a tripod around all day just for this moment.

[vizjerei]

Originally Posted by RawheaD

Not to diss your experiment; it's a very cool concept in theory :-) Just that, I can't think of practical applications for it.

taking shoot of Cityscape at night, even with ISO100 and long exp, this way will also clean up much of the noise. I tried with the Multi-exp in K10D and compare with single exp, it is much better.

[Paul Hunt]

For Linux users, Enfuse is part of the panotools library. I believe that the exposure blending of enfuse is used by hugin, but I have not used it myself.

Paul

[Vormulac]

Can these programs not handle raw files? They aren't working for me.

ETA: Ok, just converted my test files to .TIFF and they worked fine. Interesting software, shame that TuFuse stamps watermarks all over everything as it brought up the detail and contrast in the low light area better than EnFuse did.

[panoguy]

Originally Posted by Vormulac

Can these programs not handle raw files? They aren't working for me.

I can't say whether TuFuse or any Windows/ Linux apps can, but Bracketeer on MacOS can handle almost any raw file if your version of OS X is newer than the camera. Apple includes dcraw (the open-source utility to read camera raw that nearly every non-OEM software uses) with the operating system's image library.

16-bit TIFFs are also a pretty good way to go.

[wll]

If you were shooting in a concert situation, and needed 3200+ iso, could you take a shot you liked, make a duplicate of that image in PS and apply this software ----- would it work ?

If it did that would be very very cool !!!!


wll

[mithrandir]

I have compared shots using Digital Photo HDR and Enfuse for noise levels. Enfuse wins hands down.