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HDR Video a Reality

timothy posted about 4 years ago | from the dreamlike-intensity dept.

Input Devices 287

akaru writes "Using common DSLR cameras, some creative individuals have created an example of true HDR video. Instead of pseudo-HDR, they actually used multiple cameras and a beam splitter to record simultaneous video streams, and composited them together in post. Looks very intriguing."

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less than impressive (-1, Troll)

Anonymous Coward | about 4 years ago | (#33529102)

How much effort went into making a crappy moving photoshop?

Depth (0, Offtopic)

EnsilZah (575600) | about 4 years ago | (#33529106)

That's great and all but when do I get a camera that also shoots a depth map?

Re:Depth (0)

Anonymous Coward | about 4 years ago | (#33529272)

when someone hacks kinetic?

one question: (-1, Flamebait)

Anonymous Coward | about 4 years ago | (#33529118)

can you make a movie of my cock sliding into your mom's pussy?

Re:one question: (-1, Troll)

Anonymous Coward | about 4 years ago | (#33529850)

can you make a movie of my cock sliding into your mom's pussy?

For your tiny cock only a very very low dynamic range is required. Besides that I don't think I'd like to make a movie out of it due to the smell. You see, she's been buried now for over a decade. While I applaud your initiative in digging up what's left of her corpse the stench would be unbearable. And I hope you got the right one as my parents were buried besides each other. With the level of decay you would need to analyze the pelvis to determine which decomposed heap of flesh was my mom. If you didn't do that, you just might have been fucking my dad and wouldn't that be embarrassing!

Re:one question: (0, Offtopic)

archmcd (1789532) | about 4 years ago | (#33529868)

I don't know why you need me for this. She records all of her encounters in High Dynamic Range herself.

Re:one question: (0, Offtopic)

aliquis (678370) | about 4 years ago | (#33529968)

can you make a movie of my cock sliding into your mom's pussy?

I don't know why you need me for this. She records all of her encounters in High Dynamic Range herself.

In Soviet Russia High Dynamic Range records YOU sliding out of your mom's pussy?

The holy grail of camera tech.... (3, Interesting)

Above (100351) | about 4 years ago | (#33529130)

HDR

Focus Stacking

Panoramic Stitching

All in the camera, all 1-button easy to use, and all at once.

Re:The holy grail of camera tech.... (1, Funny)

blai (1380673) | about 4 years ago | (#33529224)

wtf? no intelligent aperture, unlimited storage and battery life?
wake me up when obama sends me one for free.

Re:The holy grail of camera tech.... (0)

Anonymous Coward | about 4 years ago | (#33529320)

Well, the construction crews got their stimulus 2.0.

You'll have to unionize first all camera users before you get to dip your fingers in that pot of honey.

Re:The holy grail of camera tech.... (4, Funny)

fractoid (1076465) | about 4 years ago | (#33529504)

wtf? no intelligent aperture, unlimited storage and battery life? wake me up when obama sends me one for free.

You have two of those embedded in your friggin head. :P

Re:The holy grail of camera tech.... (1, Insightful)

jd (1658) | about 4 years ago | (#33529684)

You do realize they said "intelligent". Anyone who puts a populist political slam into a Slashdot post clearly lacks intelligence.

Re:The holy grail of camera tech.... (1, Funny)

Anonymous Coward | about 4 years ago | (#33529742)

That's only true if it's the sort of populism I don't like.

Re:The holy grail of camera tech.... (1)

fractoid (1076465) | about 4 years ago | (#33529774)

I was just talkin' 'bout the eyes. No comment on the rest of 'im. :P

Re:The holy grail of camera tech.... (0)

Anonymous Coward | about 4 years ago | (#33529698)

wake me up when obama sends me one for free

One will need to exist and be in the possession of someone first, then he will take it from them to give to you. Dems don't just give stuff away. They give other people's stuff away.

Re:The holy grail of camera tech.... (-1, Offtopic)

aliquis (678370) | about 4 years ago | (#33529982)

wake me up when obama sends me one for free.

There's a stimulus plan for that, just trash 10 old cameras and they will help you out getting a new one!

But don't you dare break that one to! Then you'll only get a point'n'shoot your evil little thing!

Re:The holy grail of camera tech.... (3, Interesting)

Prune (557140) | about 4 years ago | (#33529986)

You don't need aperture at all if you use a microlens array to do integral photography. On top, you get full depth (3D) and capture all focal lengths, including the focal depth information. All in a single shot. Just need an ultra high resolution sensor--or, instead, an array of many small cameras (works just as well, and no need for perfect alignment as that can be finessed in software). You capture a full 4D lightfield (light can be parameterized as the two pairs of coordinates of a light ray crossing two infinite planes), i.e. miss no optical information whatsoever other than your diffraction and wavelength limits.

Re:The holy grail of camera tech.... (5, Funny)

Lehk228 (705449) | about 4 years ago | (#33529514)

and it also has to give BJs

Re:The holy grail of camera tech.... (4, Interesting)

Prune (557140) | about 4 years ago | (#33529960)

You forgot about full lightfield capture. This can be done with a single camera using ultra high resolution and a microlens array (or alternatively, an array of a very large number of tiny cameras). Think single camera, single shot capture of depth (3D) and all focus planes. Then you can reproduce the full 3D and multiple focus depths (as in, the eye would have to focus at different depths) on a flat display with microlens array covering it (again, need ultra-high resolution since focal depths and parallax viewpoints are discretized to the pixel number covered by each micro lens).

Re:The holy grail of camera tech.... (1)

Itninja (937614) | about 4 years ago | (#33529980)

I think we have that already (except for the button). It's called the human eye.

The trumping technology to follow: (3, Funny)

DWMorse (1816016) | about 4 years ago | (#33529194)

The trumping technology to follow: 3D-HDR Video!!

Re:The trumping technology to follow: (1)

blai (1380673) | about 4 years ago | (#33529316)

3D-HDR DVD on JVC HD AMOLED TV!!

Now explain that to your grandma.

Re:The trumping technology to follow: (3, Funny)

c6gunner (950153) | about 4 years ago | (#33529450)

"It's a motion picture in technicolor. With sound!"

Re:The trumping technology to follow: (1)

tsa (15680) | about 4 years ago | (#33529748)

With four colours per pixel!

a text C&P from the article (4, Informative)

kaptink (699820) | about 4 years ago | (#33529196)

C&P from the linked page (assuming a /.'ing imminent)

HDR demo @ http://vimeo.com/14821961 [vimeo.com]

Press Release:

HDR Video A Reality

Soviet Montage Productions releases information on the first true High Dynamic Range (HDR) video using DSLRs

San Francisco, CA, September 9, 2010: Soviet Montage Productions demonstrated today the first true HDR video sourced from multiple exposures. Unlike HDR timelapse videos that only capture a few frames per minute, true HDR video can capture 24 or more frames per second of multiple exposure footage. Using common DSLRs, the team was able to composite multiple HD video streams into a single video with an exposure gamut much greater than any on the market today. They are currently using this technology to produce an upcoming film.

Benefits of Motion HDR
HDR imaging is an effect achieved by taking multiple disparate exposures of a subject and combining them to create images of a higher exposure range. It is an increasingly popular technique for still photography, so much so that it has recently been deployed as a native application on Apple’s iPhone. Until now, however, the technique was too intensive and complex for motion. Soviet Montage Productions believes they have solved the issue with a method that produces stunning–and affordable–true HDR for film and video.

The merits of true HDR video are various. The most obvious benefit is having an exposure variation in a scene that more closely matches the human eye–think of filming your friend with a sunset at his or her back, your friend’s face being as perfectly captured as the landscape behind them. HDR video also has the advantage of reduced lighting needs. Finally, the creative control of multiple exposures, including multiple focus points and color control, is unparalleled with true HDR video.

“I believe HDR will give filmmakers greater flexibility not only in the effects they can create but also in the environments they can shoot in” said Alaric Cole, one of the members of the production team, “undoubtedly, it will become a commonplace technique in the near future. ”

Contact:
Michael Safai
Soviet Montage
201 Spear Street #1100
San Francisco, CA 94105
1 415 489 0437
mike@sovietmontage.com

Re:a text C&P from the article (5, Funny)

lgw (121541) | about 4 years ago | (#33529374)

TL;DR: in Soviet Montage, camera manages multiple exposure for you.

Re:a text C&P from the article (1)

Americium (1343605) | about 4 years ago | (#33529918)

You will able to get TV quality footage without lighting!!!

Re:a text C&P from the article (1)

BetterSense (1398915) | about 4 years ago | (#33529938)

"Filmmakers"? I think he means "videographers". I don't see any film involved here.

HDR? (4, Interesting)

afaik_ianal (918433) | about 4 years ago | (#33529200)

Can anyone give a brief rundown on what HDR is? I know it stands for "high dynamic range", but as someone who knows nothing about photography, it means nothing to me. What it has to do with overexposure/underexposure (to which the video refers)? Why is it harder to do with video than still images?

Re:HDR? (5, Informative)

mtmra70 (964928) | about 4 years ago | (#33529246)

Wiki explains it well:
 
 

is a set of techniques that allow a greater dynamic range of luminances between the lightest and darkest areas of an image than standard digital imaging techniques or photographic methods.

And their picture is a great example. If you expose the building well, the clouds are washed out. If you expose the clouds well, the building is dark. If you take pictures of both equally exposed then merge the photos, you now have a properly exposed building along with a properly exposed sky giving thus giving you more dynamic range. Think of it like instead of going to the lunch buffet and cramming everything into one plate, you go up to the buffet three times with three plates: one for salad, one for main course and one for dessert. With a little processing (trips) you end up with more range (food variety).

Re:HDR? (2, Insightful)

jack2000 (1178961) | about 4 years ago | (#33529444)

HDR looks so unreal even if at times aesthetically pleasing. Their "more real" filter didn't do the scene much justice too.
Was the guy supposed to look that way?

Re:HDR? (4, Informative)

mtmra70 (964928) | about 4 years ago | (#33529480)

HDR looks so unreal even if at times aesthetically pleasing. Their "more real" filter didn't do the scene much justice too.
Was the guy supposed to look that way?

The video was not very good at all, so I'm not sure why it is a big deal. The video of the guy was more HDR than any other part, though it was very strange.

Take a look at some of the HDR photos on Flickr http://www.flickr.com/groups/hdr/pool/ [flickr.com] . They give much better and proper example of HDR.

Re:HDR? (1)

Gerafix (1028986) | about 4 years ago | (#33529768)

[quote]Flickr http://www.flickr.com/groups/hdr/pool/ [flickr.com] [flickr.com]. They give much better and proper example of HDR.[/quote] Everything looks like clown puke. Yeah okay.

Re:HDR? (1)

lc_overlord (563906) | about 4 years ago | (#33529914)

Actually that link has mostly just tonemapped images with saturation turned up really high, some of those weren't even HDR from the beginning, while some of them use the double exposure manual cropping method, in which you expose the sky and the rest separately and photoshop them together.
True hdr should look like a normal image on a normal screen, perhaps the dynamic range can get compressed or tonemapped a little bit, but not totally.
ON an HDR display though it's another issue as it should have areas that are really dark and ones that are blindingly bright.

Re:HDR? (1)

bastion_xx (233612) | about 4 years ago | (#33529926)

Stock up on that Kodachrome while you've got time Gerafix. There's 95% crap out there no matter what the method of photography is, same holds true with HDR. Trey Ratcliff shows how it can be done in an artistic manner.

Re:HDR? (4, Informative)

ColdWetDog (752185) | about 4 years ago | (#33529506)

That's one of the problems with HDR photography. The light to dark transitions just don't look quite right and so the scene has an 'unreal' appearance. Either washed out or cartoonish.

You see that all of the time in still HDR photography and I think it has to do with the limitations of the final media - movie screens, paper, computer screens - that do not reproduce the eye's ability to deal with contrast well. In prints, you can work with this and minimize but not completely remove the effect. I imagine that they could tweak their algorithms a little better but Internet video isn't a particularly high quality visual experience in the first place so there well be some limitations in how well they can do it.

Re:HDR? (0)

Anonymous Coward | about 4 years ago | (#33529740)

That's one of the problems with HDR photography. The light to dark transitions just don't look quite right and so the scene has an 'unreal' appearance. Either washed out or cartoonish.

That means you're doing it wrong (unless that was the effect you wanted). There are typically halo effects that come about when you do HDR non-realistically. There are some really good HDR pictures that are realistic: http://www.flickr.com/groups/realhdr/pool/

(Not all are realistic, despite the group name, but several excellent examples can be found).

Re:HDR? (2, Insightful)

petermgreen (876956) | about 4 years ago | (#33529784)

and I think it has to do with the limitations of the final media
indeed, a normal monitor has a limited dynamic range. With many modern LCDs each channel is only 6 bit!

So if you want to make both the shadow and highlight detail in a a high dynamic range image visible on a normal monitor you will have to compress the dynamic range down.

Re:HDR? (5, Informative)

icegreentea (974342) | about 4 years ago | (#33529862)

You can get HDR to look 'fine' or whatever adjective you want to use. It's just hard. The tone-mapping software/settings that many people use will just go and create doll skin and haloes everywhere. But if you do everything well (hard work!) you can get some really cool looking stuff. For example...

http://www.flickr.com/photos/swakt1/2322363690/
http://www.flickr.com/photos/swakt1/2322366898/in/photostream/
http://www.flickr.com/photos/ten851/4972637653/in/pool-hdr

Somewhat like many other art techniques, when best used, you barely notice it at all. And that is the most important thing to remember. HDR + tone mapping isn't just a technology, it is an art. Being able to capture video in 3 different stops at once is great, but it'll still look like crap unless you treat it with respect and give it the effort and time needed.

Remember, HDR + tone mapping is just trying to create a low dynamic range image on a low dynamic range display that LOOKS something like what your mind perceives in a high dynamic range environment. Obviously, that's kinda hard, especially since the human eye can change its sensitivity as it focuses on different parts of a scene in real life, but not really when looking at a computer screen or print.

Re:HDR? (1, Informative)

Anonymous Coward | about 4 years ago | (#33529554)

Tone mapping and HDR are often used synonymously. Unfortunately the article also confuses HDR with tone mapping. They're two parts of the process which in combination often creates an "unreal" look. The HDR part is about capturing the higher dynamic range. The tone mapping part is about reducing the dynamic range without losing detail or color in the shadows or highlights (blue sky instead of white, texture instead of flat shadows). The tone mapping is what makes these pictures look unreal when it is overdone or performed carelessly. Algorithms for automatic, realistically looking tone mapping are still a research topic. It doesn't have to look unreal though. Tone mapping can be used to create realistic impressions. For example, in this panormic image [fotoausflug.de] , the result of tone mapping is that you can see the tables in the shadow and the blue sky with the faint clouds at the same time. Without tone mapping, you'd see a white sky or black shadows. (That picture is not an HDR picture, but it is strongly tone mapped. This [fotoausflug.de] is an HDR and tone mapped picture.)

Re:HDR? (4, Interesting)

plover (150551) | about 4 years ago | (#33529756)

One problem I realized after watching the scene with the guy is the video compression artifacts can be different between the two cameras. Even if the sensors were perfectly aligned with each other and the optics, the MPEG compression could be different because the values at each pixel will still be slightly different due to the differences in exposure levels. Different pixel values can cause different compression schemes to be invoked in each block, which will result in weird combinations of aliasing. I think this may have been partly responsible for the shimmer on his denim jacket.

Re:HDR? (1)

theJML (911853) | about 4 years ago | (#33529808)

Sounds like we'll just need to dump that video from the cameras in RAW, do the post processing and then compress it. Which is the way it should happen anyway if it wasn't for speed limitations in getting RAW 24fps 1080p video off of the camera.

Re:HDR? (4, Insightful)

im_thatoneguy (819432) | about 4 years ago | (#33529818)

"HDR" images don't look unreal. Tonemapped HDR images look unreal.

You can do the same thing to Low Dynamic Range Images, and they'll look just as unreal. Similarly you can take a 18 stop HDR image and apply normal image processing techniques and get realistic looking images.

The *only* defining aspect of HDR images is the large amount of dynamic range they contain. The fact that people abuse that dynamic range is an aesthetic one completely separate of HDR.

It's like saying that Photoshop makes images look fake. *Photoshop* doesn't make images look fake, bad artists make images look fake. You don't have to apply a stock lens flare to your family photo. It won't be too long before all cameras just shoot HDR. The largest application then will be to adjust the exposure at home without worrying about under or over exposing that shot of your friends on the beach.

And you get that awesome Halo effect (1)

bigtrike (904535) | about 4 years ago | (#33529520)

Where there are bright halos around every transition and your picture has no clear subject.

Re:HDR? (1)

Jarik C-Bol (894741) | about 4 years ago | (#33529830)

and the net result is it looks like a video game. I mean seriously, did anyone else notice that? the lighting range looks like something from a game, not quite full-bright, but the shadows just seem.. wrong.

Re:HDR? (3, Informative)

treeves (963993) | about 4 years ago | (#33529252)

It requires post-processing. You combine images shot at bracketed (above and below the "optimum") exposures, in order to get the details in both the brightest and darkest parts of the image which are sometimes lost in high contrast situations. You end up compressing (to use an audio analogy) the brightness range into a smaller range so it can be reproduced on a monitor or paper.
The post-processing of a LOT of frames requires a lot of processing power and time.

Re:HDR? (2, Insightful)

lee1026 (876806) | about 4 years ago | (#33529254)

Well, a camera can only capture so much of the difference between the brightest parts of the image and the dimmest part of the image. How HDR works is that you take one picture that is extremely dark, and then you take another picture that is extremely bright, and you merge them together so that the resulting picture can capture more of the super bright parts and more of the super dim parts. Now, the problem for video is that it is hard to take the bright shots and the dim shots at the same time, because you need for the cameras to remain where they are.

These guys solved that problem by using a beam splitter to redirect the same light to two cameras.

Re:HDR? (1)

pitchpipe (708843) | about 4 years ago | (#33529318)

How HDR works is that you take one picture that is extremely dark, and then you take another picture that is extremely bright, and you merge them together

In Soviet Montage, HDR merges YOU!

Oh wait... no, you're right. :-D

Re:HDR? (1)

nospam007 (722110) | about 4 years ago | (#33529266)

Enter HDR in Google and you don't even have to click Enter.

Re:HDR? (3, Funny)

BitHive (578094) | about 4 years ago | (#33529372)

Now you tell me! I've been trying to click enter for the last hour and it's been incredibly frustrating.

Re:HDR? (1)

Qzukk (229616) | about 4 years ago | (#33529294)

The wikipedia article is pretty good: http://en.wikipedia.org/wiki/High_dynamic_range_imaging#Example [wikipedia.org]

The idea is that you merge together overexposed photos (which show all the darker details) and underexposed photos (that only show the brightest details) to come up with a picture that has all of the details in it.

Re:HDR? (1)

internettoughguy (1478741) | about 4 years ago | (#33529312)

You start with multiple exposures, each one with a different exposure value, each of these images has a dynamic range that runs from 0-255 (one octet), these images are then stacked so that you get a floating point value image, the most common being an EXR file. Because these images are of a greater dynamic range than any monitor can display, they are either tone-mapped, where all the data is pushed back into an octet of depth, or a slice of the new image's depth is chosen.

Re:HDR? (2, Interesting)

EnsilZah (575600) | about 4 years ago | (#33529314)

I'm no expert on the subject but the basics as I understand them are you take several photos at different exposures, that way you have all the details in the dark areas from the overexposed photo, the details in the bright areas from the underexposed photo (that would otherwise be burnt out) and you can even use an HDR image for lighting a 3D scene by I guess analyzing the nonlinear way lighting changes between exposures (this area I'm a bit less clear about)

It's difficult to do for video since for a still image you just take different photos without moving the camera, so you need to share the same point of view but it can be at different times given a static scene, with video you need to share both the point of view and the time so it requires, as they did here, splitting the same image into two and having two cameras record at two different exposures.

What I'm not sure about is why you can't just use a single exposure and make copies of the current states along its duration, probably has something to do with sensor response times and or the method used to read from it being destructive.

Re:HDR? (1)

Freddybear (1805256) | about 4 years ago | (#33529326)

Gross oversimplification follows...

Given a scene with both brightly lit areas and dark shadows, film or digital sensors cannot capture the maximum amount of detail in both areas in the same picture. Compromises must be made which either overexpose the bright areas or leave the shadows underexposed. The simplest form of HDR photography tries to compensate by taking several shots of the same scene with different exposure settings, and then combining the exposures after the fact. This is difficult with moving subjects, to say the least. Trying to use the same technique with video would be even more troublesome.

It sounds like the "creative individuals" have solved the problem by enabling the use of multiple, synchronized, video cameras to record the same scene from the same viewpoint (hence the beamsplitter). Just pointing separate cameras at the same target with give parallax effects and you'd end up with a stereo 3d image instead of the HDR image when the different cameras' images were recombined.

Re:HDR? (0, Redundant)

dziban303 (540095) | about 4 years ago | (#33529366)

I'm confused as to why, 18 seconds into the movie, they show a split screen with the darker half "overexposed" and the brighter half "underexposed". You'd figure the people who put this together wouldn't get it backwards like that, but evidently they did.

Re:HDR? (-1, Redundant)

Anonymous Coward | about 4 years ago | (#33529426)

Sensors have a certain dynamic range, which is the ratio of the signal strength which saturates the sensor to the signal strength which the sensor can barely distinguish from noise. In a camera, it is the ratio of the light intensity which gives the maximum value to the light intensity which gives the value 1. If you expose for the lights, i.e. without overexposing any part of the picture, then (in many scenes) there are parts of the image which are flat black, because they fall below the dynamic range of the camera. If you expose for the shadows, i.e. there are no truly black pixels, then there are usually parts of the picture which are overexposed. HDR photography is a collection of techniques for capturing higher dynamic ranges than a normal camera can capture. The human eye has a higher dynamic range (even without adaptation) than very expensive DSLRs, so there's the motivation. What people call HDR is actually tone mapping, the processing of an HDR image so that it can be displayed with standard dynamic range display technologies (print, LCDs, etc.). Tone mapping is to images what compression is to audio (not compression like MP3 but "everything is the same loudness on the radio" compression). HDR is also not just more bits per pixel. That's intensity resolution. You can have a high intensity resolution and still only capture a low dynamic range, or you can have only 256 shades of gray but distribute them across a high dynamic range (although that would usually not be sensible).

A very common technique for capturing HDR images is making several exposures and combining the information into a single HDR picture. You expose for the shadows, you expose for the lights and, depending on the total dynamic range, you take a few exposures in between. Then these exposures are "registered" if necessary, which means they're shifted and rotated to compensate for camera movement. The stack of images is then combined. There are special programs for this which convert the image data to linear gamma, linearize the response curve of the sensor and in the end spit out an image where the ratio between the brightest pixel and the darkest pixel is bigger than a normal camera could have captured.

The process of combining several exposures is problematic for moving scenes, because then you don't take different exposures of the same scene. You take different exposures of different scenes, and this creates ghosting, or at best you have patches where you have to choose a single exposure. If you want to make HDR motion pictures, then you have to use a technique which makes different exposures at the same time. One option is a camera with a pattern of pixels with different sensitivities. Another option is to use a beam splitter with several cameras, which is what the article is about.

Re:HDR? (1)

takev (214836) | about 4 years ago | (#33529434)

HDR means you use more bits when recording the image. More than the usual 8 bits per color component. One can already do a bit of HDR when you take the raw image from most photo cameras that have 10 to 14 bits of depth. However these 10 to 14 bits are linear light (as opposed to gamma corrected for the display, so their dynamic range is not much better).

The real improvement comes from taking multiple exposures of different lengths of the same subject. Then combine these exposures into a single image; basically you would try to use the pixels from the long exposure (more accurate measurement) unless the pixel is over exposed, then you would use the same pixel from the short exposure; in reality you would use a weighted average to smooth it out a bit more. The more exposures you have the more range of accurate measurements you have.

In this case they took two cameras, set to a different exposure speed, then later they combined the two videos into a HDR image.

Now comes the interesting part, displaying the HDR image/video. You can now simply choose a virtual exposure time to show the image in a normal way, but more convenient than having to select the exposure during filming.

Or you use a special algorithm that changes the exposure of an image on a per pixel basis based on the surrounding pixels, in sort of the same way as a human eye would interpret the real world. This would show a picture with both dark a light patches very clearly, and more lively. However such algorithms always make it look fake, but it may just be conditioning that we have had looking at normal photographs (like a transistor amp compared to the valve amp).

Also from the video it looks like the algorithm used here causes flickering in the image (unless the flickering was caused by the cameras themselves), I guess the algorithm needs to be modified to take into account moving images.

Re:HDR? (2, Informative)

ADRA (37398) | about 4 years ago | (#33529494)

I'm not an expert, but from my limited knowledge:

HDR is taking frames of varying exposure levels and merging them into a single picture that contains color levels combined from both. It would help in correcting contrast washout areas of the image that aren't the target exposure of the image without needing touch ups. Taking HDR pictures at multiple exposure levels allows for a richer range of captured detail. When I overexpose in sunlight, I get an effect that takes all detail away from a darker piece of the scene. This may be intentional if I'm looking to over saturate other areas of the image using optical capture techniques. Having the same effect could be simulated in post processing by adjusting levels of specific parts of the image, but that's more time consuming and may not lead to the best results. Having one image under exposed and another overexposed means that the richness of each color range can be captured as they were when shooting. That gives a director a lot of power in changing the composition of a shot without needing to re-shoot or do more laborious processing techniques.

It is hard to do period, because any optical capture device has a set exposure that they are capturing for. The other issue is that the image has to be identical basically identical. Any variation (such as time delay between image captures) can cause ugly or unwanted side-effects that would require cleanup later on. Applying this principle to video capture, you -could- have a camera and single lens/sensor taking images at twice higher speeds, but that means reducing the possible exposure times by at least half which ultimately limits the possible lighting conditions that one could shoot HDR in (hard/impossible in the dark?). One could shoot two cameras simultaneously, but then again the problem is that because the images aren't exactly perfect which would lead to ugly artifacts. For close ups, this is all but infeasible because these artifacts become larger and more apparent. Think of this as the anti-3D concept. You want two pictures being taken at the same time, but instead of having them offset based on the capture view plane, the photographer wants them as close to identical in terms of angle / offset as possible. For 3D-HDR movies, you'd need at least 4 simultaneous frames being captured at all times (two left, two right)

These guys' solution seems to be taking one lens and by applying an beam splitter (http://en.wikipedia.org/wiki/Beam_splitter) (which ultimately reduces the amount of incoming light) cuts the frame identically between two channels which gets fed into two Canon cameras (capturing video) who are set to varying exposure timings. They've chosen to use 2 stops+/- and I don't really know if that's the ideal for HDR capture or if its just the maximum automatic exposure variation they can choose in the 'pseudo-auto' exposure modes built into the cameras.

Re:HDR? (1)

Jackie_Chan_Fan (730745) | about 4 years ago | (#33529686)

Basically the range of light that exists in reality, far exceeds the recording capability of most devices, including our eyes.

Our eyes are actually one of the best at reacting to very dynamic ranges of light.

Cameras have varying degrees of dynamic range, but most of them, if not all (as far as i'm aware of) cant capture the full range of light.

Put it this way... In real life, light ranges from 0 to 1. 0 being the absolute absense of light, and 1 being the brightest thing possible. (I'm not sure we know what that is yet) :)

Cameras can not capture the full range of 0 to 1. They instead have to be controlled creatively by the user, or an automatic process, that averages out tonal values to 50% grey. And then the camera captures its + or - from that 50% average... until it hits its recording limitations of bright and dark. This essentially clips the bright, and the dark when it hits that limit.

But what is bright and what is dark? You actually have the ability to control that, by chosing where to place your camera's limited range, within the real worlds full dynamic range. This is what is known as an exposure. So lets say your camera can only record a range of 0 to .5 Well thats .5 less than the full range of light in the real world. That means you can slide your exposure around. You could expose your photo so that it records the ranges of light from .2 to .7 That means what is 0 (absolute black) in the real world, will not be captured in your exposure. But it doesnt mean that "Black" wont be in your exposure. It just means that what is RGB 0,0,0 black in your photo, is actually not absolute black in the real world.

Now what is HDR? HDR is a way of capturing a larger range than yoru camera is capable of doing. Usually by using multiple exposers. Since we know that our example camera can only capture a range of light from 0 to .5... Then if we took 2 exposures, one which captures 0 to .5, and then a second exposure, from .5 to 1... we have captured the full range of light... We simply need to join the images together.

This is where it gets tricky because not only do cameras have limitations in how they record light... but our display devices such as monitors, projectors, printers also have a limitation in the range of tonal values they can reproduce...

So while we can record larger ranges of light by using multiple exposures.... We still have no way to actually SEE all of that ranges of light... unless we merge them back into a low dynamic range.

The best example of this is outdoor photography. Outdoor photography has a serious problem in that range of light on a bright sunny day is amazingly dynamic and large. The sky is so bright... you have to chose camera settings to balance the brightness of the sky, and the darkness of the ground/subject matter.

Obviously you do not want lovely green grass to look too dark. You'd like to see that vibrant, bright green that we associate with nature. The problem is when you expose the grass, to get that pleasing look, the sky that is blue in real life, becomes white in the camera because the camera can not capture the amount of light properly. It actually over exposes the sky. The reason is because our camera captures from 0 to .5, and in the images that come out of our camera, 0 is black, and .5 is white. BUT IN REAL LIFE... 0 is black, .5 is grey... and 1 is white.

Our camera has to squeeze the range into its own limited range. In real life that blue sky isnt white, so its clearly not 1 in real life range. Its probably more like .75 Which is still out of range of our camera.

If you take two exposures you can capture both the grass in that lush vibrant green, and the the sky as a deep summer blue... But you have to combine them to get the proper look your eye saw that day when you took that photo.

The problem is people often over do the merging. They can easily make a photo look magical or unreal.. surreal, or just dumb... if they merge the photos wrong.

The reason why VIDEO HDR is a big deal has to do with how cameras work. Cameras work on a shutter+iris+sensor combination ... and the combination of those 3 various elements can have various effects on the image recorded. To get different exposures you have make choices on how you use those 3 variables to expose your image properly. The problem is in video... those 3 things would have to be adjsuted on the fly... and they would actually add various things into the image such as blur or a varying depth of field (focus area), etc that would be noticeable in a video because it would be happening as you watched the video.

One way around this is to simply make better sensors so that we can capture larger ranges of light. Now in video, a lot of video is recorded in 10bit color spaces or larger even.

Our monitors and most cameras deal with 8 bit color ranges when they output data. Most SLR cameras these days deal with 10 to 14bit range of color, which means they capture more tonal range than our monitors and printers can display, but they still do not capture the full range of light. :)

But those larger bit depth sensors/recording formats... such as canon's raw format, or nikons raw format... or ILM's EXR... or SONY HD RAw... You can capture more tonal value without messing with the shutter+iris+sensor variables. Sure you have to make a choice for your exposure... but the exposure recoreded will capture a larger range of light allowing you to adjust exposure later on a computer, rather than by using the traditional mechanical shutter, iris, film speed combinations.

BUT AGAIN.. it still doesnt capture the full range of light :)

BUT this helps in video... because now your video has a higher range recorded.... which allows more creative choices in post.

hope that makes sense... it probably doesnt.

Re:HDR? (1)

petermgreen (876956) | about 4 years ago | (#33529790)

Dynamic range is the ratio of the smallest signal you can detect (under a given set of settings) and the largest.

If your dynamic range is too small for the scene then no matter what exposure you chose you will lose detail in some parts of the image.

Cameras have a much smaller dynamic range than the human eye so scenes that our eyes deal with no problem can pose a problem for cameras.

High dynamic range imaging gets around this by taking two or more exposures. Longer exposures (or wider apetures or higher sensor sensitivity) for the dark parts of the image and shorter exposures (or equivilent) for the bright parts. Software can then combine these images to produce one high dynamic range image.

For stills of static scenes this is easy however for video (or worse stills of fast moving objects) there is a problem. If you try and use one camera your images with different exposures will be taken at different times. If you try and use two cameras with seperate lenses the different viewpoints will cause an issue. The soloution to this is to use beam splitting optics.

Very impressive! (3, Interesting)

WilliamGeorge (816305) | about 4 years ago | (#33529228)

I've been a long-time fan of HDR photography, and was just thinking about ways that HDR could be implementing in video camcorders as well. Personally I'd like to see a correctly-exposed stream mixed in with the other two, as is common in photography, but even without that the effect is pretty darn cool.

By the way, in case any camcorder manufacturers are watching, consider this idea: make a video camera with three (or more) times the required number of sensors for the resolution you want to record at. Set the logic in the device up to use three unique sets of sensors inside to pick up three different sets of images, at differing exposure settings. Then have them saved separately so that they can be integrated later on for various editing effects - or have a mode where they are integrated on-the-fly for easier use by non-professionals. I imagine it would be expensive to make such a complex sensor and camera, but it might be easier to manage than multiple cameras as the folks in the article did.

HDR == High Dinamic Range (1)

cab15625 (710956) | about 4 years ago | (#33529256)

Just in case anyone was wondering. It would be nice if editors would get into the habit of making sure that the front page summaries had a definition of these TLA's in at least 10% of the posted articles. TLS == three letter acronym, by the way.

Re:HDR == High Dinamic Range (4, Funny)

blai (1380673) | about 4 years ago | (#33529298)

TLS == three letter acronym

Cool

Here I was thinking HDR video was old hat (4, Informative)

scdeimos (632778) | about 4 years ago | (#33529260)

Wasn't the first HDR video camera back in 1993? Granted, they called it Adaptive Sensitivity [technion.ac.il] back then.

Re:Here I was thinking HDR video was old hat (1)

jd (1658) | about 4 years ago | (#33529702)

The first still HDR camera was developed in the late 1800s. The chances are extremely high that video HDR dates back much earlier than 1993. The chances are extremely high that garage developers had started work on such devices before sound had been introduced.

Re:Here I was thinking HDR video was old hat (2, Interesting)

forkazoo (138186) | about 4 years ago | (#33529820)

Spheron had an awesome single-sensor HDR video camera demo at SIGGRAPH this year. It records 20 stops of latitude, and after some processing for debayering and whatnot, you get an EXR sequence. I got to see it live, in person, and stand a few feet away from the camera. The guy running the demo even let me play with some footage in Nuke on the demo laptop. I'm confused about why a hacked up beamsplitter based system would be so noteworthy, when the single-sensor method will suffer less light loss thanks to the simpler optical path.

I'm sure the guys who did this project are proud of what they pulled off, and it's probably a neat hack, but I have to assume they are sort of operating in a vacuum if they think they have really invented something newsworthy.

tried it out recently (2, Interesting)

frank_carmody (1551463) | about 4 years ago | (#33529264)

I had my first foray into HDR still photography recently and I have to say I'm very very impressed with the results. Certain night-time scenes look absolutely stunning using 4-5 exposures. Here's some shots by a friend of a friend: http://roache7.deviantart.com/gallery/ [deviantart.com] .

why not capture the 14 bit/channel of 1 sensor? (1)

Mike Zilva (785109) | about 4 years ago | (#33529282)

I have an EOS 550D (aka T2i) and the raw still format capture 14 bit per channel, so it sould be also available for video mode, even if it requires a custom format.

Re:why not capture the 14 bit/channel of 1 sensor? (0)

Anonymous Coward | about 4 years ago | (#33529392)

Keep in mind that most high res cameras are limited by bus and storage speed. Sure it can take 30MB raw images but can it push them down the pipe at 60 per second?

Re:why not capture the 14 bit/channel of 1 sensor? (1)

MobileTatsu-NJG (946591) | about 4 years ago | (#33529428)

I'll be up front and tell you I don't know the answer, but I imagine the camera can't write the uncompressed data fast enough and there isn't a (standard) codec right now that can reasonably make it smaller and compress fast enough with the processors available.

Odd lighting issues (2, Insightful)

T Murphy (1054674) | about 4 years ago | (#33529288)

In the video, there is a part showing a man talking, and eventually he waves his arms around. At that point, you can see some parts of the picture become brighter near his arms- clearly not shadows, so it must be an artifact of the HDR processing. Anyone care to explain what might cause this, or how it might be addressed? I don't know much about HDR so I wouldn't have a clue, but some insight into the technical stuff behind the process would be interesting (and help people like me better learn and appreciate HDR).

Re:Odd lighting issues (2, Informative)

EnsilZah (575600) | about 4 years ago | (#33529394)

I haven't noticed it and now it's been slashdotted so I can't confirm but I imagine that if they used two different exposures on the cameras then on the longer exposure a fast moving object would be blurred so at its core it would be darker because it's always blocking the light while at the edges it would be lighter since it's only blocking the light part of the time.
So I guess it would create edge artifacts because of the mismatch between the short exposure which has less motion blur and is mostly at the same level of brightness and the long exposure which has the edge blurring.
And I would think that you could solve that with a neutral density filter rather than using different exposure lengths.
I'm this is all one big assumption though.

Re:Odd lighting issues (1)

T Murphy (1054674) | about 4 years ago | (#33529486)

The video is here [vimeo.com] . Thanks goes to the guy who copy/pasted TFA in anticipation of a /. .

Re:Odd lighting issues (1)

jd (1658) | about 4 years ago | (#33529720)

If you take a look at the still photographs at the LOC from the photographer who toured Russia in 1913 or so, you'll see that anything moving splits into the components as a function of the speed of motion. I would imagine something similar is taking place here, albeit to a smaller degree because of the higher speed of the film and not needing to swap filters physically.

Re:Odd lighting issues (1)

Bo'Bob'O (95398) | about 4 years ago | (#33529780)

I think it was bloom in the higher exposure version.

Re:Odd lighting issues (5, Informative)

arcsimm (1084173) | about 4 years ago | (#33529846)

The bright spots are indeed an artifact of the HDR process -- partulcarly the tone-mapping algorithms. On its own, HDR is basically a method of capturing intensity values that would otherwise fall above or beneath the threshold of a camera's sensitivity. The problem is, when yo do that you end up with image data that can't be completely represented within the gamut of a printer or a screen. You could simply display a "slice" out of the data, which results in a regular images at whatever exposure setting you've chose, or try to "compress" the tone values into your available gamut, which results in a washed-out appearance. This is where tone-mapping comes in. What tone-mapping does is try to compute the correct exposure levels on a per-pixel basis, by comparing its intensity relative to nearby pixels. Ideally, this results in shadows being brightened to the point where you can see detail in them, and blown-out highlights brought toned down (analogous to "dodging" and "burning" in terms of old-school darkroom film processing -- the dynamic range of film is much higher than that of photo paper).

In practice, though, you end up with weird highlights around dark areas, like the ones you saw around the man's arms, because the tone-mapping algorithm is trying to maximize the local contrast in the image. It's brightened up the coat, and so it also brightens nearby pixels to compensate for the reduction in contrast. Some people try to adjust the algorithms to minimize this effect, while others try to maximize it for dramatic effect, or even an oversaturated, impressionistic look -- it's largely an artistic choice, though when done badly it can also be a sign of amateurism. Still others will manually composite multiple exposures to get the benefits of HDR imaging while avoiding its side effects entirely,

The Wikipedia article on tone-mapping [wikipedia.org] goes into great detail on the different approaches to HDR photography, if you're interested.

Re:Odd lighting issues (1)

T Murphy (1054674) | about 4 years ago | (#33529902)

Having posted the question I can't use mod points here. I think a +5 informative is in order.

Re:Odd lighting issues (3, Informative)

icegreentea (974342) | about 4 years ago | (#33529920)

You're seeing a moving halo effect. Most tone-mapping processes have trouble with dark on light transitions. Basically, in an attempt to 'smooth' out the transition between lightening/darkening, you get the lightening effect bleeding from the dark regions to the lighter regions creating a halo. If you watch the starting sequence with the buildings, if you look at the right side with one building in the foreground, and the dark side of another building in the background, you can once again see the halo effect. Just go google around HDR images, and you'll see it everywhere. It's very hard to get rid of, and simply put, if you run any tone-mapping process on default, you'll end up with them.

It's basically the result of the software not being able to tell with confidence where the boundaries between higher/lower exposure is, so instead it assigns an approximate that "plays it safe" in one direction, and then smears out the boundary. Basically photoshop's magic selection wand + feathering.

slashdotted already (1)

jamcc (792681) | about 4 years ago | (#33529296)

already slashdotted. who knew.

erm... (0)

Anonymous Coward | about 4 years ago | (#33529310)

first shot. isn't the dark part (left) underexposed and the bright (right) part overexposed?

Or is Reality a HDR Video? (1)

BitHive (578094) | about 4 years ago | (#33529350)

It really makes you think...

Slight mix-up in video captions (1)

Andy Smith (55346) | about 4 years ago | (#33529356)

The results are beautiful, in my opinion. HDR looks great when done with restraint. I've even used HDR for work a few times, such as this "portrait of a truck" for a haulage company:
http://www.flickr.com/photos/meejahor/2073616479/sizes/z/ [flickr.com]

There's a slight mix-up in the video captions though. Where the captions say underexposed and overexposed, they've got the terms the wrong way round. Probably just a language barrier thing, though, as it's a Russian team.

Re:Slight mix-up in video captions (1)

Andy Smith (55346) | about 4 years ago | (#33529402)

Before anyone jumps in to point out my mistake, the team might not be Russian after all. I didn't know until now that "Soviet Montage" (company name) is a film-making technique.

Yes but? (-1, Redundant)

The Living Fractal (162153) | about 4 years ago | (#33529416)

Not pr0n? Fail!

Re:Yes but? (1)

jack2000 (1178961) | about 4 years ago | (#33529464)

Trust me you want porn capturing equipment to stay the way it is. You do not want to be staring at the tiny hairs in glorious future resolutions and HDR exposure magic.

YES (0)

Iburnaga (1089755) | about 4 years ago | (#33529430)

I want to watch a full movie using HDR.

Unimpressed (4, Informative)

Ozan (176854) | about 4 years ago | (#33529442)

The technique is promising, but the provided example video does not demonstrate a true advantage it has over conventional cinematography. They filmed with two cameras, one overexposing one underexposing, but they don't have one with the right exposure to compare with the composed HDR images. The city scenes are filmed at daylight, without any areas of high contrast that would make a high dynamic range necessary. The same with the people example, they even overdid it to give it a vibrant effect, making it more of an artistic tool than capturing shadows and lights naturally.

They should make a short film with city nighttime and desert scenes, that should be impressive. They should also contact director Michael Mann, he would jump at the opportunity to film HDR.

Old (1)

WilyCoder (736280) | about 4 years ago | (#33529524)

Call me a bitter old man, but wake me up when they have cheap HDR displays available to purchase so we don't have to do tonemapping on HDR images. I've been into HDR for a while and tonemapping KILLS hdr, it makes it look cartoonish.

There are VERY few cases where I have seen HDR done right. Everyone thinks HDR means using bloom like its going out of style... /grumpy

Re:Old (0)

Anonymous Coward | about 4 years ago | (#33529578)

Wake up, bitter old man.

Re:Old (1)

Gerafix (1028986) | about 4 years ago | (#33529760)

99.9% of HDR photos I've seen look like clown puke. Now we'll be able to watch clown puke videos, yay.

I guess it has its uses... (1)

owlnation (858981) | about 4 years ago | (#33529572)

But, I have to say I wouldn't be someone who would ever use this. I can see the merit for some stills, I can see some use for documentary, I can see the merit for amateurs wanting to capture a wedding, or for limited VFX scenes in motion pictures, but as a cinematographer this is pretty much the opposite of what I would ever want to achieve.

Give me chiaroscuro every time. You only have to look at the work of Conrad L Hall, Gordon Willis, Caleb Deschanel or Nestor Almendros to name but a few, to see how beautiful shadow, silhouette and darkness can be.

HDR gives far, far too much information, and produces very flat images for motion pictures, in my opinion.

True advancement in video technology (3, Insightful)

LoudMusic (199347) | about 4 years ago | (#33529662)

This is so much better than 3D technology. It's even better than high definition video. This is actually the process of creating better images. I am actually really excited about this!

What about more dynamic range in the sensor? (1)

RNLockwood (224353) | about 4 years ago | (#33529744)

At work we routinely create images with 12 bits of dynamic range. It's trivial to map this for 8 bit display. We use monochrome sensors, though, and I don't know if if the dynamic range is available for color.

no thanks (1)

rongage (237813) | about 4 years ago | (#33529812)

This looks to me like the video equivalent of audio compression - squeezing the life out of the media to make it fit within a certain constraint,

Thanks but until the entire chain is HDR, I'll pass.

Ron

LOL, OBAMA'S PRESIDENCY IS GOING DOWN IN FLAMES (-1, Troll)

Anonymous Coward | about 4 years ago | (#33529822)

The job's not so easy when your ass is the one in the fire, is it douchebag? I'm enjoying every minute of you eating humble pie.

This isn't new... (1)

archmcd (1789532) | about 4 years ago | (#33529852)

I've been purchasing Wide Dynamic Range cameras for 3 years now for my company. They make for fantastic surveillance cameras. By the way, WDR is even more dramatic than HDR (though this is only theoretical, as there's no industry standard definition of HDR vs WDR). I think this is only new in that multiple high-resolution full-motion cameras have been used in conjunction with one another to create a very high quality video stream in HDR, whereas the surveillance cameras I've purchased are only 4CIF and I only record about 4-8fps with them, certainly not high resolution or full motion.

HDR/WDR is fantastic technology, and its niche has been in surveillance, but very few people even in the surveillance industry have recognized the benefits. WDR allows you to see vivid facial features in extreme backlit shots or excessively dark environments.

Is it me... (1)

Superdarion (1286310) | about 4 years ago | (#33529946)

Is it me or does that look exactly like newer videogames with heavy textures?

I had no idea what HDR was so when I started looking at the video I actually thought it was a videogame. Kindda reminds me of COD MW.

This is not HDR (1, Flamebait)

Trogre (513942) | about 4 years ago | (#33529950)

It it was true HDR then we'd need a (non-existent AFAIK) HDR monitor to see it. This is two exposures compressed down to a standard dynamic range image, aka fake HDR.

The novel part here is in the simultaneous capturing process of these two exposures.

The fatal flaw... (1)

edw (10555) | about 4 years ago | (#33529976)

Unless they're somehow collecting at least twice as much light, assuming that the beam splitting is perfectly efficient, then I fail to see how what they're doing really helps, as both of the images (or image streams) are going to wind up being shot at at least twice the ISO that they otherwise would be. That would not be good for sharpness and noise. There better be a large lens collecting light for these cameras.
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