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Mars images rendered in 4K [video]

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Re: Mars images rendered in 4K [video]

#81

Post by nitrogen »

soylentcola wrote: post #8
magnetic wrote: post #2

In my youtube quality menu, it only goes up to 1080p. Is this really 4K?

Mine goes up to "2160p" but since the source photos are stitched together, I'm not sure what their total resolution would be (probably varies based on what/how many were stitched together). It's basically some pans across high resolution composite images. Quite cool but not captured video. As they mention, there's not much moving there anyway but it will be cool when someday we can look at high def (or even stereosco…

You can get stereoscopic images from the Curiosity navigation cameras. You could do a much better job of correcting the lens distortion, but I made an example in 2012 (I decided to make the sky blue as a stylistic choice at the time, for which I was rightly criticized as Mars does not have a blue sky and people might think the images were from Earth): https://blog.mikebourgeous.com/2012/08/06/curiositys-view-of...

Re: Mars images rendered in 4K [video]

#82

Post by cbsmith »

1_player wrote: post #69
magnetic wrote: post #27

Earlier quoted context omitted.

MacBookPro with Safari.

Safari hasn't supported >1080p in years (because it blocks VP9 and Youtube has stopped offering higher resolutions in H264 that Safari supports)

Yup. Golden rule: don't use Safari for YouTube (or really for video content in general).

Re: Mars images rendered in 4K [video]

#83

Post by astroflask »

cryptoz wrote: post #70
nobrains wrote: post #33

Interesting facts that I didn't know before seeing this video: - The opportunity rover captured a barren scene which was named Rub Al Khali (Yes! On Mars!), named after the Rub Al Khali desert area which touches UAE, Saudi, Oman and Yemen. (1) (2) - The video says that Mars rovers send back images (not videos) and then those images are stitched together to create videos, because "nothing ever moves on Mars". But I wo…

Mars is constantly moving. There are wind storms, dust devils, ice melting, all kinds of things. Here's a dust devil https://www.youtube.com/watch?v=k8lfJ0c7WQ8 (again, it's still images to make a video) but not because "nothing ever moves on Mars"! Mars is constantly shifting and changing with its weather and seasons. Ice caps freeze more, and ice caps melt more, water or other liquid flows down hills when it gets w…

Earlier this year I made a video[0] where I took two images which are frequently posted on reddit that show the movement of martian sand over a day and interpolated (with python and opencv) the movement into a smooth video. I'm currently working on restoring some Apollo footage, but one of the pending projects is taking the Curiosity descent sequence (at 4 frames per second) and give it a shot at some nice quality, XXI century interpolation (we have some very good algorithms now, or at least better workarounds the artifacts).

[0] https://youtu.be/k7pfdFMVj-o

Re: Mars images rendered in 4K [video]

#85

Post by astroflask »

shakezula wrote: post #58
majora2007 wrote: post #22

A lot of people bashing on this, but I think overall it's pretty impressive just showcasing to more people what Mars looks like. I for one was impressed and enjoyed the panoramic effect. Crazy to think Earth might eventually look like Mars.

Anyone bashing on this has absolutely no concept of the scales or engineering that went into this. When I look at these images, even though I've known we had them for a long time, I'm filled with a tiny bit of hope for the future, something I haven't had in all of 2020.

Some of the bashing is because of the over-the-top narration, and the script saying things that are borderline lies. It's not the first time this images have been seen. It's not the first time someone has rendered them in 4K video (I'm pretty sure Astrum and Scott Manley have used some of these images before).

When looking at the title at first I thought they had used an SR-GAN (or modern variant) to upscale the images. And no, they just took the images and pan over them. I wouldn't have liked the SR-GAN approach either, I'm not a fan of it (to me it trades accuracy for good looks, and it introduces some artifacts which, while harder to spot on video, are probably not really there).

Also others have pointed out that it seems like basically monetizing public domain images without putting some effort into it. Like another crows has pointed out, they do work into writing a script, the narrator, and editing the material, so that's not a take I like (and I'm also "in the same business" as them).

Re: Mars images rendered in 4K [video]

#86

Post by astroflask »

nabla9 wrote: post #52
hijp wrote: post #10

The narrator explains why getting HD video would be impractical, but I disagree that we get the same experience from panning stills. imagine seeing the swirling dust, shifting sands, the bumps and parallax from a moving rover. that would be so cool!

Very little shifting sands. Winds in Mars have almost no strength. Air pressure in the Mars surface is very low, something like 1% of Earths. Dust devils and storms are made of extremely fine powder.

The movement shown in this video[0] happened over the span of a martian day. Do not dismiss the winds of Mars, as they have also killed[1] a couple of rovers already.

[0] https://youtu.be/k7pfdFMVj-o

[1] They have also breathed new life on one of those (before killing it, yes) by cleaning the solar panels. I'm referring to the MER Rovers Spirit & Opportunity.

Re: Mars images rendered in 4K [video]

#87

Post by crazygringo »

cbsmith wrote: post #80
crazygringo wrote: post #66

Earlier quoted context omitted.

If you're talking about a beautifully mastered Blu-Ray, then that might be true. But given how aggressively YouTube compresses videos, watching in 4K can provide a huge improvement over 1080p even if your screen only has, say, 1,600 lines like my MBP does, instead of the 2,160 lines that 4K actually produces. It's really about the clarity of textures and how lifelike they are -- it's very noticeable. Of course, this…

That's curious. My observation has been that most of the streaming services have really high compression ratios with 4k streams. With videos like this one, which are built from still images, I imagine you still get significant improvements in quality, but for content that isn't so easily compressible (e.g. action movies), I've seen significant effects from compression in 4k streams as compared to "regular" 4k source…

That's exactly what I'm saying, though.

Because YouTube (like other streaming services) aggressively compresses both 1080p and 4K, but the 4K version still has a much higher bitrate, watching the 4K stream on a 1080p monitor will be significantly better quality than watching a 1080p stream on a 1080p monitor.

I'm not saying you won't see any compression artifacts at all, of course if it's an scene you will. But the 4K version is still noticeably way better than the 1080p one, even in an action scene. It's a higher bitrate so there's more detail no matter what.

Re: Mars images rendered in 4K [video]

#88

Post by btkramer9 »

dylan604 wrote: post #57
MVorlm wrote: post #29

Earlier quoted context omitted.

10 minutes is the the milestone for "mid-roll" ads. As far as I can tell, this video has no ads in the middle.

"As far as I can tell" by your comment, you did not watch the video. I didn't even finish half the video, and I stopped it just before the 2nd ad break started.

maybe they have an ad blocker? I too watched the entire video and didn't see a single ad. Beginning, middle or end. I'm using adblock plus

Re: Mars images rendered in 4K [video]

#89

Post by cbsmith »

crazygringo wrote: post #87
cbsmith wrote: post #80

Earlier quoted context omitted.

That's curious. My observation has been that most of the streaming services have really high compression ratios with 4k streams. With videos like this one, which are built from still images, I imagine you still get significant improvements in quality, but for content that isn't so easily compressible (e.g. action movies), I've seen significant effects from compression in 4k streams as compared to "regular" 4k source…

That's exactly what I'm saying, though. Because YouTube (like other streaming services) aggressively compresses both 1080p and 4K, but the 4K version still has a much higher bitrate , watching the 4K stream on a 1080p monitor will be significantly better quality than watching a 1080p stream on a 1080p monitor. I'm not saying you won't see any compression artifacts at all, of course if it's an scene you will. But the…

Yeah, what I'm saying is that because the 4k streams are trying to convey more entropy than the 1080p streams, I've observed that even though their bitrate is higher, the resultant compression effects are far more severe, to the point where the overall experience is better with 1080p, sometimes even if you have access to the full 4k resolution. I've seen similar effects with audio content (after a certain point, increasing sampling rate significantly more than bitrate has a deleterious effect).

From an information theory perspective, you are obviously correct that there is more information in the 4k streams and therefore you will get more detail from them. My observation however has often been the opposite.

My attempt to rationalize leans towards notions that the lossy compression techniques we use with video codecs still have significant impedance with the "compression" in our neuro-opthalmologic system.

Re: Mars images rendered in 4K [video]

#90

Post by salgernon »

jerf wrote: post #54
nobrains wrote: post #33

Interesting facts that I didn't know before seeing this video: - The opportunity rover captured a barren scene which was named Rub Al Khali (Yes! On Mars!), named after the Rub Al Khali desert area which touches UAE, Saudi, Oman and Yemen. (1) (2) - The video says that Mars rovers send back images (not videos) and then those images are stitched together to create videos, because "nothing ever moves on Mars". But I wo…

"There is a beautiful selfie at timestamp 6:41" Where's the camera in that selfie? Perhaps edited out of the mosiac?

There's an explanation and video[1]; I remember thinking the same a few years ago.

[1] https://www.nasa.gov/feature/jpl/nasas-curiosity-mars-rover-...

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