HDR Video a Reality 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."
Re:HDR? (Score:3, Insightful)
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.
Odd lighting issues (Score:3, Insightful)
Re:HDR? (Score:3, Insightful)
Was the guy supposed to look that way?
True advancement in video technology (Score:4, Insightful)
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!
Re:The holy grail of camera tech.... (Score:1, Insightful)
You do realize they said "intelligent". Anyone who puts a populist political slam into a Slashdot post clearly lacks intelligence.
Re:HDR? (Score:3, Insightful)
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? (Score:5, Insightful)
"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.
Re:HDR? (Score:3, Insightful)
Re:Very impressive! (Score:3, Insightful)
That's crazy. You'd get practically the same effect just by alternately under/over-exposing successive frames. From there you could interpolate whatever level of exposure you wanted without losing too much detail.
Re:Unimpressed (Score:2, Insightful)
I'm unimpressed for a different reason.
I think this is extremely interesting, and definitely worth reading about and watching.
However, I just can't get into HDR. There was a point when HDR photography was sort of a novelty, interesting, but now I'm sick of it. Even when it's done well it looks odd, and I fear the same thing would eventually happen with video.
I hope people take your perspective to heart, I really do. However, I anticipate this will be a dead end in much the same way it has become with still photography.
I realize you're saying that this technique could be made more useful, but I've become so sensitized to HDR effects that any of it looks like a gimmick to me.
Re:HDR? (Score:3, Insightful)
Well of course not. It's a compression into a small dynamic range that our 8 bit per color channel (hahahahah!) monitors provide.
And, unless we go back to per pixel light generation and get rid of this backlight nonsense (full power for a black image!?), I'm not sure I want a screen bright enough to provide decent HDR!
Re:The holy grail of camera tech.... (Score:2, Insightful)
Re:HDR? (Score:2, Insightful)
They record HDR but then they compress the image to LDR (low dynamic range) for display on a regular monitor. You don't see the HDR display, just the result of the tone-mapping algorithm that transforms the HDR data into an LDR one. This is a common abuse of the term HDR. It's the same thing with the graphics effect in games. The internal processing is HDR, but then it's tone-mapped to LDR for display on a regular monitor, often with the addition of simulated bloom on overexposed areas. It's unfortunate that so many people see bloom and think HDR, but then again marketing is a common factor in many forms of misinformation.
No, you fucking moron, you are simply 100% WRONG.
For this video, they are recording in LOW RANGE (YUY2 or YV12), and then combining the stills of two different video streams in order to futz the two LOW RANGE videos taken at different SPACES in the sensor's RANGE into a single LOW RANGE video that preserves the RANGE of each separate image DYNAMICALLY in certain AREAS of the final, LOW RANGE, video.
For HDR photos, the only difference is that they're shooting in their camera's RAW format (or they should be) so they have more control over how each individual photo is level-mapped to the final output photo.
HDR is DESIGNED for LOW RANGE DISPLAYS.
There is no such thing as a HIGH DYNAMIC RANGE display. This would be a display that artificially adjusts contrast levels in specific areas of the display while still living in the fixed contrast level of the overall display.
HDR images on an "HDR display" would be DOUBLY molested.
An HDR image on a high range display would look just like an HDR image on a low range display. You could stretch the contrast of the image artificially via some filter built into the display, but this is no different than stretching 4:3 content to fill a 16:9 display.
When you're talking about HDR photos being compressed to LDR, what you're referring to is the mapping of RAW, 12-bit, 16-bit, etc. images to an 8-bit space. This process has NOTHING TO DO with HDR, regardless of whether or not you've applied HDR to a set of RAW images.
Again, there is no such thing as a LOW DYNAMIC RANGE display. There is no such thing as a DYNAMIC RANGE display. All displays are fixed range, and all image formats are fixed range.
The "dynamic" in HIGH DYNAMIC RANGE means that the contrast WITHIN dark/light areas is preserved, but the overall original-to-output brightness mapping is DYNAMIC; the mapping is different for different areas of the output image.
In the following examples, the widths of things represent the contrast / color range.
This is a normal photo:
[___SCENE____CONTRAST____RANGE___]
----exposure----[SENSOR_RANGE]----
Take picture, with a set exposure offset, record sensor data.
[SENSOR_DATA]
Map sensor data to image format of choice for final display.
JPEG: [SENSOR_DATA] --> [JPEG]
Something better than JPEG: [SENSOR_DATA] --> [BETTER_FORMAT]
RAW: [SENSOR_DATA] --> [SENSOR_DATA]
This is an HDR photo:
[___SCENE____CONTRAST____RANGE___]
------exposure------[SENSOR_RANGE]
---------[SENSOR_RANGE]--exposure-
[SENSOR_RANGE]------exposure------
Take multiple pictures at different exposure settings, record sensor data.
[SENSOR_DATA]1
[SENSOR_DATA]2
[SENSOR_DATA]3
Combine [SENSOR_DATA]s into a single image by defining different areas and combining them:
Area 1: Use [SENSOR_DATA]1 and futz edges with [SENSOR_DATA]2
Area 2: Use [SENSOR_DATA]3 and futz edges with [SENSOR_DATA]1
Area 3: Use [SENSOR_DATA]2 and futz edges with [SENSOR_DATA]3
Area 1 + Area 2 + Area 3 = [IMAGE__DATA]
Note the widths of [SENSOR_DATA] and [IMAGE__DATA].
Map image data to image format of choice for final display.
JPEG: [IMAGE__DATA] --> [JPEG]
Something better than JPEG: [IMAGE__DATA] --> [BETTER_FORMAT]
RAW: [IMAGE__DATA] --> [IMAGE__DATA]
Re:HDR? (Score:2, Insightful)
You're an idiot.
Not only is that display not using the same principles as HDR photos, it's not calculating the contrast ratio in any way that makes sense.
HDR is any image, video, display, or camera sensor that contains more than 8 significant bits per pixel per channel.
YOU HAVE NO IDEA WHAT HDR MEANS.
High
Dynamic
Range
Each word means something.
RAW formats are NOT 12-bit.
RAW formats are WHATEVER THE CAMERA SENSOR GRABS.
8-bit. 10-bit. 12-bit. 14-bit. 16-bit. IT DOESN'T MATTER. And no, they are not HDR. They are simply a higher range than your shitty 8-bit jpegs. There is nothing DYNAMIC about them.
NOBODY IS CONFUSING ANYTHING WITH TONE MAPPING.
DYNAMIC has a MEANING.
LOOK IT UP.