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World's First Full HDR Video System Unveiled
Zothecula writes "Anyone who regularly uses a video camera will know that the devices do not see the world the way we do. The human visual system can perceive a scene that contains both bright highlights and dark shadows, yet is able to process that information in such a way that it can simultaneously expose for both lighting extremes – up to a point, at least. Video cameras, however, have just one f-stop to work with at any one time, and so must make compromises. Now, however, researchers from the UK's University of Warwick claim to have the solution to such problems, in the form of the world's first full High Dynamic Range (HDR) video system."
Now p0rn can be filmed in sunlight and shadow at the same time!
Why, without your clothes, you're naked, Miss Dudley!
Personally, I think the HDR screen described, with HDR videos, would be more interesting and immediately useful than the ever-so-commonly-advertised but ever-so-rarely-purchased "3D" screens.
Didn't a pair of guys do this last year using a pair of DSLR's and a beam splitter?
Also ,unless someone is building a HDR display this is all pretty academic, HDR images have to have their range compressed and then tone mapped in order to be displayed via conventional means, this is normally terribly unsubtle and results in an image that looks not entirely unlike it was rendered using 3d modelling. If we are going to see another big shift in display (read: TV) technology in the next decade I would much rather we moved away from the sRGB / YUV colour space than started fucking about with HDR content, what's the point of trying to take advantage of our eyes exposure latitude if we can only render 1/3 of colours?
I first learned about HDR from Valve, during one of the developer commentaries on one game or another... (Lost coast maybe? Anyways) They were trying to explain how Bloom is done in video games, and certain other effects like how walking out of a dark tunnel to bright light will affect your vision for a tiny bit, as your eyes need to adjust to the new lighting conditions.
Thats when I started looking it up and yeah, basically the idea is that you take one shot that is under exposed (dark), one shot that is over exposed (light) and one that is properly exposed, and as many more in between as you want. Then you feed it all into a bit of software which takes the richest colours and lighting conditions from each photo and imposes them into one single image, so the dark corners remain dark and the bright lights remain bright and the vivid colours are still vivid. Its quite cool stuff.
I'm a little curious as to how this is working, is it managing to encode the HDR real time into it's range compressed and tone mapped beauty at least 24 frames per second, or does it merely record the 3 or more images simultaneously and then take a few minutes afterwards to do the encoding? The first I think would be more impressive, but not really necessary.
http://www.panavisionimaging.com/imagers_DMAX.htm
i get the feeling lots of people have been working on this.
I mean, we have 1080p 3D stereovision with full-micron surround color effects, and yet, movies still stutter like mad on a fast pan because that damn 24 fps capture rate just can't keep up. Is it really so much harder to capture 60 fps and encode than it is to do a working 3D effect? I'd pay more for movies that have reliable framerates in the 60 Hz range than I would for 3D.
Those who can, do. Those who can't, sue.
They claim
"more representative description of real world lighting by storing data with a higher bit-depth per pixel than more conventional images"
So basically they store the image with greater color resolution then the conventional 8bit-RGB -- they are not getting realtime over/under exposure passes to get HDR enhanced mixed output.
Two companies already dealt with this in the past, though they aren't doing as much with the technology as one would hope.
1 - Fuji has a sensor that does HDR already. Several years ago, in fact. It has two overlapping layers of sensors and takes two images at the same time, then blends that two together. Done, can buy it today. Just it isn't in use in a video camera yet(and their current camera doesn't do video very well)
2 - Foveon also has a different sensor approach where it is layered like film. This gives it the same dynamic range as our yes, or very close to it. It produces amazingly clean and beautiful images. But the resolution of the sensor is fairly low at about 4.5MP. Though, those are real full-color photosites (no interpolation or moire as ther is no "pattern" to the sensor), so it compares with a typical 10-12MP camera. Still, it's fairly low. Yes, their latest camera does do HD video, which is quite nice.
The OP can be forgiven, though, as these two companies spend almost nothing on advertising these two technologies. I'd wager that only one in 20 or 30 people who are interested photography and video (that I talk to) even are aware of them. A normal person just simply doesn't know at all.
We just think they are. We change our focus and view, squint, shift our heads, and shade our eyes to avoid brightness to view dark areas. Video cameras can do most of that, too, plus they can zoom, something eyes lack. The problem is representing that view on a monitor, which does not have the dynamic range of the real world. Photographic prints that have HDR compensation may look surreal, and others look washed out in places. Video has the same issues. It takes a lot of post production to make it appear normal.
Is this the same HDR that the iPhone 4's still camera has?
Do daemons dream of electric sleep()?
Video cameras, however, have just one f-stop to work with at any one time, and so must make compromises
Just to name one example, the Red One has a wonderful dynamic range of 11.3 stops. http://en.wikipedia.org/wiki/Red_Digital_Cinema_Camera_Company
I wouldn't say that most cameras have a "real" dynamic range of 10 f-stops (the upper and lower stops are usualy just a result of interpolation and thus cannot really be used in practice). Only top-notch ones have 10-11 f-stops (a average DSLR camera does not have more than 6 usable stops).
However, your point is clear, definitely much more than one.
It does not matter that a camera can only have one aperture and one ISO setting. Our eyes have only one iris, as well. What matters is that our retinas & brain have a dynamic range that trumps CMOS/CCD sensors. Oh, and the fact that our eye cheats by seeing more colour in the middle of the retina and more bright/dark & movement in the corner of our eyes.
That being said, I am looking forward to anything that extends the dynamic range in both cameras _and_ displays.
Not quite. HDR is a very fundamental change because it doesn't just change the resolution, but the range. Currently we store and display images in a range from [0,1], 0 is black, 1 is white. We can store that range in 5bit or in 8bit per color and thus get a higher color resolution, but it will still just be the same range of [0,1]. Photographing a white paper and the sun both gives you a 1.
With HDR on the other side you move beyond that range, you basically switch from integer to float (or just integer with a different range mapping). Instead of [0,1] you get something like [0, 6.55 × 10^4]. Thus you can accurately represent the difference between looking at a white paper and staring into the sun, information that would have otherwise been completely lost.
As our displays will still only have [0,1] range, you have to tone map the HDR images down to that range, but the additional information you have allows a lot of post processing tricks that would otherwise be impossible.
Not quite 10-13 f-stops.
A DSLR camera sensor captures 5 f-stops of dynamic range, both CMOS and CCD sensors, taken in RAW format. Even the latest EOS 1D series still has 5 stops to work with, down to the consumer class DSLR's.
What these guys have done is create a system that can capture 20 stops worth of dynamic range, which is fantastic. But TFA is light on technical details on whether these guys have created a new chip design or if multiple sensors are used.
But i love this choice quote from TFA:
"It consists of an LED panel which projects through an LCD panel placed in front of it. The combination of the two screens is necessary to provide all of the lighting information."
Note the emphasis on the word 'through', as if using an LED panel as a backlight for an LCD display is something new or special.
Hilarious.
The word "dynamic" has a meaning.
This is not an "HDR" display, nor does such a display exist, nor would anyone want one.
This is an "HR" display.
"The new system, by contrast, captures 20 f-stops per frame of 1080p high-def video, at the NTSC standard 30 frames-per-second. In post-production, the optimum exposures can then be selected and/or combined for each shot, via a "tone-mapping" procedure."
They're using the typical method of taking many exposures of the same frame. Makes sense.
I would hope they're using an image/video format that can store exposure data per pixel. (But I know they're not - they're using a separate file per frame that maps each pixel or macroblock to an exposure value).
"The final step in the process is the HDR monitor. It consists of an LED panel which projects through an LCD panel placed in front of it. The combination of the two screens is necessary to provide all of the lighting information."
So basically, the monitor is super fucking bright, and then it's made lighter or darker based on another monitor in front of it acting as a dynamic screen.
I don't care whether or not the system works well or not. (I'd have serious questions about compatibility with editing software, storage space, the viewing angle of a double-screen system, etc.) What I do care about is them using the range dynamic. If the range (of brightness) of the entire screen (every pixel) is the same, then it is not dynamic range. The range of the screen is simply [LEDS OFF + LCD CLOSED] to [LEDS ON + LCD OPEN]. Certainly way better than shitty, shitty, 24-bit color and the corresponding brightness range (humans care far more about luminance than chrominance, so RGB alone was a bad choice for color representation). But the word "dynamic" has a meaning. If the range doesn't change across the screen (and why would you want that), it's not dynamic. The brightness changes over time, but the range is fixed.
The dynamic in HDR photography means different sections of the image are exposed or level-adjusted differently from other sections of the same image. The range refers not to the display range, or the image format, but to the SOURCE MATERIAL.
There is no such thing as an HDR DISPLAY, and there never will be.
Now there is an HDR video camera when are we going to have an HDR video monitor? Seems kind of useless to have an HDR camera with no way to display it.
Well, there are situations where you need multiple exposure to avoid clipping some details. E.g. images like this one: http://hdrcreme.com/photos/23496-Entrance-of-a-Small-Church There is no way a consumer camera can get the detail of the interior of the dark room (and the colorful window) as well as the bright outsides.
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RED has shipped its first two production EPIC-M cameras which has a feature called HDRx, which allows up to 18 stops of DR in a single exposure for every motion picture frame. It doesn't require a beam splitter or any other gadgetry.
Peter Jackson has a number of them he's using for the Hobbit. I think the latest Spiderman is shooting with it too.
It does that at 5K, which is 5120x2880 resolution.
As to comments that HDR is better than 3D, or that you don't need lighting... they are unfounded. You still need lighting to create the precise mood you want. The advantage is that you can now create that mood more easily in more lighting conditions. This is especially important in conditions that the film maker can not control. The first RED demo was a shot from inside a barn out the barndoor into the Arizona desert. The camera held detail in the shadows inside the barn and in the sky and on white surfaces in direct sunlight.
The normal solution to that lighting situation is to pour about a hundred thousand watts of lighting into the inside of the barn, hope nothing catches on fire and that you are close enough to the sun
Don't post innacurate information
If you do, I swear by my pretty floral bonnet I will end you.
Didn't Autodesk Toxik 2008 already do HDR compositing with RED cameras?
Not only that, didn't they sell it to real live customers?
This is not the first, it's not even notable, frankly
All DSLR's sold today do better than 7 stops. You have to go back to the Nikon D1 to find something near 7 stops. And what does "10% or so" mean?
The system proposed claimed 20 stops which is preposterous. It was a BS article written by someone fundamentally ignorant of photography
For some arbitrarily pessimistic definition of "6 usable stops" maybe so, but every DSLR EVER has had more than 6 usable stops by any reasonable definition. Ignorant photographers, most of whom are self-professed experts with a film background, like to say 6 usable stops based on a personal, arbitrary standard of having some number of usable shades of gray in the lowest "stop" without realizing that those shades define additional stops. Those fools, among them you, confuse stops and zones. 32 shades of gray in 6 "usable stops" is actually 11 stops of dynamic range. That is what is typically possible in today's DSLRs.
o.k. - attention-grabbing subject line aside... I can't RTFA b/c it's slashdotted, so I don't know exactly what dynamic range we're talking about. But the much hyped Red Epic camera (sequel to the Red One) has full-motion HDR, and is shipping as of this month. Models with this feature range from around $10k to around $40k - so admittedly more prosumer than consumer.
It stores the extra data in a secondary video stream, so that you can tone-map in post. And apparently, it can be dialed up & down, so that you can trade off dynamic range vs. resolution (up to 5k) vs. framerate vs. compression. Pretty sweet.
You defined a stop, not an f-stop. You are not alone in the confusion. There is a big difference between the dynamic range of the sensor, in stops, and the exposure settings necessary to utilize it. The author of the article doesn't understand that either.
A system with 1 stop of dynamic range can only produce white or black, there is no "50% gray". If you use more than one bit per pixel with such a system, everything between 0 and maxpixel is noise. If it weren't then, by definition, the system would have more than 1 stop of range.
A CCD was operated at 100 Hz instead of 50Hz (PAL) and alternating frames had different exposure times. The two interleaved video streams were merged in real time into a high dynamic range image and then compressed into a standard dynamic range image where details could be clearly seen in both dark and bright areas.
This was connected to a videoconferencing system and worked very well when the room lights were turned off for a projector. You could see both the presenter's face and the projected image. A standard camera showed the projection as a white washed-out rectangle and the rest of the room around it was almost completely dark.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
HDR photos you find on the web are actually tone mapped photos. They were HDR when they were captured, or when different exposures were combined into a single image, but after that stage they were tone mapped in order to make all the details visible on a conventional display.
Tone mapping is something we may stop doing when we have proper HDR displays like in this article. A display like that will more closely resemble the real world, and tone mapping will be unnecessary because our eyes can handle high dynamic range images just fine.
The perfect HDR video system would be one where you could film inside of a dark cave and you would see everything on the screen after your eyes had adjusted to the dark, and when the camera moved outside into the sun the intense brightness of the screen would make you squint.
Cheesy tone mapped HDR photos make your eyes hurt for totally different reasons.
A witty
"The human visual system can perceive a scene that contains both bright highlights and dark shadows, yet is able to process that information in such a way that it can simultaneously expose for both lighting extremes"
Completely untrue. Any decent DSLR should have better dynamic range than the human eye. When you look at a scene, you see the overall picture and it seems clear, but really at each instant you're seeing a small clear area in a detail and all the rest of the scene in much less detail. You don't notice it because they eye and brain adjust quickly to optimize light sensitivity for what you're paying attention to instant by instant--wherever you look, it looks good. The parts without so much detail you don't notice because you're not paying attention to them. You can resolve a lot of detail in dark areas when you focus on them, and you can resolve a lot of detail in lighter areas when you focus on them--but not at the same time. They eye can pull so much detail out of any scene because it's actually making a completely different, customized exposure for each little bit of the scene as it moves around. That's why a camera that captures the entire scene in one exposure has such a hard time competing--it's not that the imaging sensor isn't as good as the human retina, it's that it's actually doing a completely different thing. And that's the impetus behind HDR--taking a number of exposures optimized for different light levels and combining them so that each part of the scene is properly exposed, just as the eye does when it looks over a scene.
I was posting the image (which isn't mine) to make a point, not to praise it. That said, I think it still looks pretty interesting in grayscale. In some ways I actually like it better desaturated.
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