Open Source Image De-Noising 205
GREYCstoration is an open-source tool able to de-noise, inpaint, or resize 2D color images. This is a command-line program developed by the IMAGE team of the GREYC Lab in France and is available for Unix, Mac, and Windows systems under the CeCILL license. The algorithm is based on anisotropic diffusion partial differential equations. These equations are able to smooth an image while preserving its main structures. The demo page presents interesting examples of color image de-noising and reconstruction. This is a serious free alternative to commercial products like Noise Ninja or Neat Image that perform the same kinds of operations. The tool is still a little bit hard to use (command-line based), but I hope the simple C++ API will ease the integration of the algorithm in more user-friendly interfaces. Previous versions of GREYCstoration are already available in Digikam and Krita.
No more ISO 80? (Score:2)
Re:No more ISO 80? (Score:5, Informative)
The lower ISO you can get the more detail you could capture given that other parameters are fixed. Have you ever shot with Velvia ISO 50 film? -- it creates stunning details. I think Fujifilm discontinued it last year or so. In film the lower the ISO the finer the grain. As far as digital is concerned think of ISO as sensitivity of the CCD. You can turn the gain up to ISO 3200 but you will amplify a lot of noise too.
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Yeah, looking at the demo pictures I see this is basically replacing noise with blur.
I was thinking about this recently, and I think what we need is a digital camera which can somehow take multiple short exposure shots one after the other and then combine them into a single photo. The algorithm would have to be smart enough to detect movement of both the camera and the scenery in-between frames, so we're talking advanced software, but it does seem possible.
Otherwise, having to choose between underexposed
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The idea is that you can eliminate blur caused by camera movement by taking many short exposures (high noise because of the short exposure), then align and average them together to eliminate the noise. This will work, but the downside is that it does require computationally intensive image alignment (to remove the camera movement that would have caused the blur in the first place) But that could be done offline.
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They already exist. [olympusamerica.com]
"Digital Image Stabilization" (Score:2, Informative)
Digital Image Stabilization Mode uses a high ISO sensitivity and fast shutter speed to enable you to [blah blah blah]
Nothing fancy here about combining multiple exposures and detecting camera/subject movement; just using higher sensitivity than the 50 or 100 that many P&S users are used to, resulting in faster shutter speeds.
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Oye
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Beware though, as you stray away from the sweet 50mm focal length you will pay astronomical prices for fast lenses...
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Not so fast (Score:2, Informative)
http://www.robgalbraith.com/bins/content_page.asp
It's a new formulation, which they're tentatively calling "Velvia II," so don't write off Velvia 50 just yet
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Company talk, you gotta love. Always read between the lines, kind of like talking to women...
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He-he, that's funny -- it desribes my wife too well. Every time I go to put food in there, the huge pack of Velvia and color infrared film is in my away. It's been like that since we got married. I keep telling her to switch completely to digital and she tells me I don't know what I am talking about, she is probably right...
Re:No more ISO 80? (Score:4, Informative)
I too have a fridge full of film (Velvia, Astia, Provia), however I accept that I'm a dinosaur and proud of it! Modern digital SLRs perform better than 35mm film in practically every respect and challenge medium format in quality. Only with large format is that not true - and large format is something of a niche! Soon of course even this will bow to the digital revolution.
I suspect she's like me, stuck in the past and quite happy to stay there for the time being! There's still something magical about transparency film. The colour reproduction is very special, with a gamut wider than you can sense in either prints or monitors. Although the gamut of modern digital sensors is just as good, there's no way of actually sensing it, as the display devices aren't up to snuff! Wide gamuts make an enormous difference to an image. The colors you see in nature are far more diverse than those that can be reproduced in print or on a computer screen. It's only by actually seeing these things first hand that one can appreciate the difference, prints look strangely grey an lifeless in comparison.
Ah, transparency film!
I'll stop evangelising now - I'm probably preaching to the converted anyway!
Responses (Score:4, Informative)
Also, in response to your later post, what many DSLRs do for long exposures (usually taken at night and with high ISO and experience a lot of noise in the black areas) is to take another exposure immediately after the first one, but with the shutter closed. Then, the camera knows where the sensor noise is and can subtract it from the actual picture.
So if you take an 8 sec. exposure and your camera freezes up for the following 8 sec, you'll know why.
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I regularly find I want to fix things in post-processing, but noise isn't one of them. I find getting stuff like color balance, constrast, brightness, saturation etc. very hard to get right out directly from the cam, but usually the auto se
ISO myth (Score:3, Informative)
Has ISO rating being abused by digital photography so much that nobody concerns shutter speed, aperture, and lighting anymore?
What fundamentally matters for high motion scene is faster shutter speed. Higher ISO sensitivity makes sure the picture is more easily exposed. Bigger aperture, as well as the scene being well-lit, let more light into the lens, so these two factors also help with exposure.
It is probably best illustrated by shooting a night scene. With dSLR or SLR, you can program long exposure o
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Get a better camera and you won't need to clean them up at ISO 400 and sometimes not at ISO 1600. Nikons new entry level DSLR, the D40, can take outstanding photos at ISO 1600 and even boosted to 3200 looks better than most P&S cameras do at ISO 200-400.
Canon makes some terrific DSLRs as well, some with even better high ISO performance, I'm simply more familar with the Nikon line.
The real question is... (Score:4, Interesting)
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Open Source giveth, and Open Source taketh away.
BTW, how's that the 'war against spammers'? Sounds like this weapon is FOR spammers.
Re:The real question is... (Score:4, Insightful)
Usually in wars people on both sides have weapons. Otherwise the war doesn't last very long.
Anti-CAPTCHA tools only help the Blind (Score:3, Insightful)
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90% of what I do on a computer is working with text, and blind people have been able to read for a VERY long time.
Hell a significant amount of people on this very site would claim to never do any work outside an xterm.
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I should think that would be easy. 8^)
You've obviously never met a restaurant owner before.
Bring 'em on, I'm on a roll, here! 8^)
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So, I don't think the spammers will be using this, unless spammers have really moved their operations on to the Linux platform.
Picture Cooler (Score:5, Informative)
But if you want images with less noise, try and buy a camera with a larger sensor. dSLR's have large sensors as do many Fuji cameras including their tiny P&S models. Most sensors on subcompact P&S cameras measure only 5.76x4.29mm (1/2.5"). Many of the smaller cameras by Fuji use a 1/1.8" sensor that measures 7.18x5.32mm.
A nice explanation of noise and sensor size is here: http://www.clarkvision.com/imagedetail/does.pixel
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FREE Picture Cooler--Noise reduction and most other adjustements 2.45 -- last update 5 JAN 2007
Temporaly 15$ for the Full version
And now enhance the image... (Score:2, Funny)
Artificial noises (Score:5, Interesting)
This pyramid photo [ensicaen.fr] has basically been 'ruined' after the denoising, I wonder if we added some synthetic noises in the background while leaving the stone face as is, would this app be able to denoise correctly?
Seeing paterns? (Score:2)
This pyramid photo has basically been 'ruined' after the denoising ...
Do you think? Are those details in the stone any more real than those in the sky? Some may have been lost, but I'm having a hard time deciding which should have stayed. The picture was sad to begin with.
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Does it work on 12 or 16 bits/channel images? (Score:5, Informative)
This tool looks very cool, but today's semi-pro and pro (and even some consumer grade) cameras will store their images in a raw format which preserves 12 bits per color channel at a minimum.
GIMP can't deal with these. Tools such as ufraw can convert them to 8 bits/channel images such as JPEG but don't allow you to actually manipulate the image in its native color resolution.
Linux seriously needs a good image manipulation tool such as the GIMP with 16-bit or even 32-bit per color channel support built-in. This is particularly important for operations like sharpening.
Cinepaint will do it but it's way behind in features compared with GIMP these days.
What's the hold up with GIMP anyway? You'd think its developers would take this kind of issue seriously and would fix the engine to natively do, say, 32 bits per color channel internally.
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With that, how about GIMP gets USABLE before ya cram in more "features".
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So Photoshop on the Mac behaves the same way the GIMP does on Linux? Interesting.
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Kind Regards
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What is your problem? I never said I was "vexed" with the way mac's work, I don't have a problem with it, it's what they're designed for.
And as for your ridiculous insults, the "dweebs" designed and built your beloved mac mate.
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Only in the same way that having a small heap of books on the floor is just a particular form of a bookcase.
Seriously, I dunno why he got modded flamebait, but the GIMP interface _is_ horrible and every non-geek I've tried to convert to GIMP found it horrible. It's not even just the heap of disconnected windows. Just about everything in it works non-intuitively, or in some own way that breaks any reflexes and expectations you might already have.
A
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I understand GEGL [gegl.org] will be the new backend for GIMP, supporting deeper color among other things. A friend closer to GIMP development mentioned to me that it may be ready for GIMP sometime this year, but neither the GEGL website or quick searches turn up anything on that topic. A 2003 thread [mail-archive.com] stated that a move to GEGL would be very gradual so as not to necessitate major rewrites.
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It is rather odd that such a thing isn't deep in the Linux world given Cinelerra has been around for years for video.
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If you are going to use more than 8 bits then using 16-bit "half" floats, or 32 bit floats, is a much better use of the space, and modern processors are easily able to keep up with this. It also helps a lot if the floating data represents linear light levels, rather than the log or gamma curve data th
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I use ufraw to convert to 16bit/channel images (png, pnm etc) and then use either my own software or Krita to work in that space. Jpeg and GIMP are only brought in at the end (if at all) to make "user level" images for web or printing. 8 bit is fine for the result, but you do need more space to work in for manipulations.
TWW
Sample of method applied to video? (Score:2, Interesting)
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I'd very much like to see a temporal version of the inpainting algorithm. They might be onto the next big step in automated morphing, smoother slow motion, or tweening for low frame rate animation.
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If this can be applied to a section of a video frame, I wonder how long it will be before video munging apps can strip out the network logos (the duck image in the impainting section gave me this idea)?
Except for SpikeTV or FX... this thing doesn't seem like it can extrapolate 50% of a frame.
Great for flying games (Score:2, Interesting)
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Cool (Score:2)
http://www.greyc.ensicaen.fr/~dtschump/greycstora t ion/img/res_ski.png [ensicaen.fr]
On a more serious note, this look pretty useful. I've been able to get quite good results on many images with a combination of blurring, denoising, unsharp masking and other algorithms in Photoshop and the GIMP, but nothing beats a proper anisotropic diffusion. And in the versions of the aforementioned software I've used, there's no such thing available (maybe in newer versions,
Anisotropic diffusion (Score:5, Informative)
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If you're interested, the video card version needs to be modified to work with non-MRI images, but here's a fairly general purpose Python implementation. It's not long, so it's easy to see what's going on. It also happens to be faster (last I checked) than the C++ version included in the ITK medical image processing
Same effect (Score:5, Funny)
Photoshop Gets The Job Done (Score:2, Informative)
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All right, slashdotters.... (Score:5, Funny)
Re:All right, slashdotters.... (Score:4, Funny)
Greg Brady did this kind of stuff 30 years ago - when he was in a high school photography class!
Reading? No. (Score:2)
I realize you're most likely joking, but I really am sick of people making this mistake. Just because you can "enhance" an image does not mean that any piece of software can be fucking psychic.
I don't see what the point is (Score:5, Funny)
Sheesh, n00bs! (Score:3, Funny)
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Image reconstruction with resynthesizer (Score:5, Informative)
It can also take one image and repaint it in the style of another image, so you can take a black and white photo and a pencil sketch as inputs and end up with your photo rendered using parts of the pencil image which are similar in form.
Another trick it can pull is creating tileable textures from any image. Sometimes the results are a little surprising if you start off with a picture of people at a party but they are totally seamless.
It comes as a GIMP plugin and is easy to use if you are used to the GIMP.
Just me or... (Score:2)
Now that's all well and good ... (Score:2)
Related software (Score:3, Insightful)
Maybe not just loss of contrast (Score:2)
memory use (Score:2)
I hacked it into my image processing library a year or so ago:
http://www.vips.ecs.soton.ac.uk/index.php?title=GR EYCstoration [soton.ac.uk]
The big issue was memory use: at least for the version I adapted, it needs 20x as much memory to run as the size of the image you want to process. So a 3k x 3k 8-bit RGB image needs 1GB of RAM. I blame CImg (I think). It needs reimplementing in a more practical image processing library. The results are nice though, if you play with the parameters a bit.
GIMP plugin (Score:2)
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I'm an old-time slashdotter (don't be fooled my my uid, it's my third account), and as most others, I seldom read TFA.
Anyway, thanks for the info.
Other software by D. Tshumperlé (Score:3, Informative)
Also consider CImage [sourceforge.net], by the same author. CImage is a C++ image processing template library (cue to how much C++ sucks compared to the language du jour and/or LISP/Python/Haskell/OCaml, etc
Concerning the inpainting algorithms that many here find impressive, there has been lots of work in this area. One of the seminal works is the paper at ICCV'99 by Efros and Leung [cmu.edu]. Many CS people will love that one since it is a fairly straightforward extention of the 1948 Markov model proposed by Shannon himself for the automated production of pseudo-english text (i.e. texts that look and sound english but really aren't). The Practice of Programming [bell-labs.com] book by Kernighan and Pike makes use of that algorithm to compare various languages in a fun way.
The Tschumperlé algorithm works on different principles and is much faster, but their particular Markov model shows the impainting problem is not that difficult in practice.
Gimp Plugin (Score:3, Informative)
Gimp plugin can be found here: http://www.haypocalc.com/wiki/Gimp_Plugin_GREYCst
It does ok and can salvage some photos, some, it can't.
Thanks Freshmeat!! ^H^H^H^H^H^H^H^H^H^H Slashdot!!
Re:Color me impressed! (Score:4, Insightful)
I disagree. They are overly smoothed and detail is destroyed. They look like the type of thing a noob makes upon discovering video filters. For example, look at the delicate features in the jellyfish or the pig's hair. This samples look more like demonstrations of soften or posterization filters. They should also use real, not artificial, noise.
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Oh yeah, baby. You the PRO! (Score:2, Informative)
They are overly smoothed and detail is destroyed. They look like the type of thing a noob makes upon discovering video filters. For example, look at the delicate features in the jellyfish or the pig's hair. This samples look more like demonstrations of soften or posterization filters.
Sure, he's a noob [ensicaen.fr]. That DT-MRI of gray matter paths in your brain based on diffusion tensors is purely the stuff of rank amateurs! Bah, next you will tell me free software authors can make a powerful and easy to use image
Re:Oh yeah, baby. You the PRO! (Score:5, Insightful)
Being a research scientist doesn't necessarily qualify someone as having a photographer's eye. Nobody's saying the guy couldn't research circles around any of us. What the parent poster said is his de-noise filter is way too aggressive and obscures image detail. That appears to be true, at least judging by the settings he's using for his demo shots.
Sufficiently advanced noise is indistinguishable from the stuff that comes out of a cheap imaging device
Not really true, because the noise that comes out of any imaging device (cheap or otherwise) is not random. It fits a particular profile that's unique to that model of device, or even that particular unit. Advanced photo filtering algorithms (including those used in the in-camera processors that convert raw image data to jpg image files) use that individual profile to filter noise. They're not trying to figure out what's noise and what isn't on the fly, which is at best an imperfect science, and that's being charitable. They have a good idea before they even look at an image what the noise is going to look like, so they do a better job of removing it without sacrificing detail.
The more advanced filters like NeatImage are also almost infinitely configurable in what noise they go after and where, and how aggressive they are. Now, this guy's algorithm seems to be pretty configurable as well, so maybe he just didn't use very good settings himself on most of his image demos, and the algorithm is actually capable of better results. He does seem like he's a better scientist than image-maker so that's entirely possible.
It would be interesting to see what could be done with this if it was given an intuitive GUI and put in the hands of some real photographers. (Yes, even real photographers have to shoot at ISO 800 and above occasionally, and would benefit from noise reduction that actually works without sacrificing detail.)
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Anisotropic diffusion works quite well. The example images DO look over smoothed, but that's just because he's got his k value cranked way up, probably to show the effect more clearly.
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He did use real noise. (Score:4, Informative)
They should also use real, not artificial, noise.
Check out very impressive clean up of a PDA camera [ensicaen.fr]. That's good. Ordinary smoothing filters blur important details, like those in the watch or the baby's ear. How nice that it is already in Digikam, one of the easiest to use photo managers out there.
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Look at the top of the ridge in the inner ear and the wrinkles in the fabric. The near-blacks also look like they've been darkened a bit and flattened (lines between the baby's fingers.) It's still a little too posterized. With natural subjects there's a point at which it's very hard to remove noise without destroying detail. These samples are all overly smoothed. They're not horrible, they're j
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I therefore challenge you to put your money where your mouth is, and clean up one of the sample images better than the filter, posting a link here.
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Re:He did use real noise. (Score:4, Informative)
Note especially the better details in the baby's collar, and faint wisps of hair on the right forehead, which are distorted or gone in the GREYCstoration. Note also the colored noise which is completely removed by Neat Image. In short: better details throughout.
This is not to say that GREYC can't do better, though. That depends on how much it can be tweaked.
Re:He did use real noise. (Score:4, Interesting)
Similar, but less so: http://www.greyc.ensicaen.fr/~dtschump/greycstora
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