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About: "I wonder if other species would look at our images or listen to our sounds and register with horror all the gaping holes everywhere.", yes. In particul

by thih9 7mo ago

About: "I wonder if other species would look at our images or listen to our sounds and register with horror all the gaping holes everywhere.", yes. In particular, dogs: > While people have an image frame rate of around 15-20 images per second to make moving pictures appear seamless, canine vision means that dogs need a frame rate of about 70 images per second to perceive a moving image clearly. > This means that for most of television’s existence – when they are powered by catheode ray tubes – dogs couldn’t recognize themselves reliably on a TV screen, meaning your pups mostly missed out on Wishbone, Eddie from Fraisier and Full House’s Comet. > With new HDTVs, however, it’s possible that they can recognize other dogs onscreen. Source: https://dogoday.com/2018/08/30/dog-vision-can-allow-recognize-dogs-tv/ https://dogoday.com/2018/08/30/dog-vision-can-allow-recogniz...

ulfw 7mo ago
What does frame rate have to do with being able to recognise a creature? If I watch a video in 10fps it looks shite but I still recognise everything on screen
- drysart 7mo ago
  It's about being able to perceive it as a "living" moving creature and not something different. You can understand something below the perception threshold is supposed to be a creature because you both have a far more advanced brain and you've been exposed to such things your entire life so there's a learned component; but your dog may simply not be capable of making the leap in comprehending that something it doesn't see as living/moving is supposed to be representative of a creature at all. I've personally seen something adjacent to this in action, as I had a dog over the period of time where I transitioned from lower framerate displays to higher framerate displays. The dog was never all that interested in the lower framerate displays, but the higher framerate displays would clearly capture his attention to the point he'd start barking at it when there were dogs on screen. This is also pretty evident in simple popular culture. The myth that "dogs can't see 2D" where 2D was a standin for movies and often television was pervasive decades ago. So much so that (as an example) in the movie Turner and Hooch from 1989, Tom Hanks offhandedly makes a remark about how the dog isn't enjoying a movie because "dogs can't see 2D" and no further elaboration on it is needed or given; whereas today it's far more common to see content where dogs react to something being shown on a screen, and if you're under, say, 30 or so, you may not have ever even heard of "dogs can't see 2D".
  - harrall 7mo ago
    But how can you tell if it was lack of recognition? I wouldn’t be interested in a 2 FPS video either — in fact I would probably avoid looking at it, whether I recognized the humans in it or not.
    - drysart 7mo ago
      I mean it's a dog so you can't exactly ask them; but this was a dog that would bark at every other dog. If he wasn't barking at Hooch because Hooch was only showing up at 24 FPS, then I'm inclined to think he didn't recognize Hooch as another dog.
- maverwa 7mo ago
  With CRTs I would think that the problem may be that they do not see a full picture at all. Because the full screen is never lit all at once? Don’t know how persistence of vision works in this case…
- afiori 7mo ago
  With Cathode ray TVs only a single pixel at a time is on, it relies on our eyes having bad enough temporal resolution, if you have Superspeed eyes you will see just a coloured line/pixel moving on screen
  - kevincox 7mo ago
    That's not quite true. Only one pixel is being activated at a time but the phosphors continue to emit light for many pixels. In practice you get a handful of lines lit to varying degrees at at time. Maybe 1-2 lines quite brightly lit and then a trail of lines that are fading pretty significantly (but still emitting light). They yes, our persistence of vision fills in the rest to provide the appearance of a fully lit screen. This video has some great slow-mo of CRTs https://www.youtube.com/watch?v=3BJU2drrtCM&t=160s https://www.youtube.com/watch?v=3BJU2drrtCM&t=160s
__alexs 7mo ago
> While people have an image frame rate of around 15-20 images per second to make moving pictures appear seamless, This is just...wrong? Human vision is much fast and more sensitive than we give it credit for. e.g. Humans can discern PWM frequencies up to many thousands of Hz. https://www.youtube.com/watch?v=Sb_7uN7sfTw https://www.youtube.com/watch?v=Sb_7uN7sfTw
- zacmps 7mo ago
  Badly phrased but not wrong, this is the minimum frame rate for humans to perceive motion as supposed to a slide show of images. The maximum frame rate we can perceive is much higher, for regular video it's probably somewhere around 400-800.
  - Gigachad 7mo ago
    Maximum depends on what it is you are seeing. If it’s a white screen with a single frame of black, you can see that at incredibly high frame rates. But if you took a 400fps and a 450fps video, I don’t think you would be able to pick which is which.
- nandomrumber 7mo ago
  NO YOU ARE! > make moving pictures appear seamless True enough. NTSC is 30fps, while PAL is 25fps. The overwhelming majority of people were happy enough to spend, what, billions on screens and displays capable of displaying motion picture in those formats. That there is evidence that most(?) people are able to sense high frequency PWM signals doesn’t make the claim that 15 to 20 frames per second is sufficient to make moving pictures appear seamless. I’ve walked in to rooms where the LED lighting looks fine to me, and the person I was with has stopped, said “nope” and turned around and walked out, because to them the PWM driver LED lighting makes the room look illuminated by night club strobe lighting. That doesn’t invalidate my experience.
  - toast0 7mo ago
    > NTSC is 30fps, while PAL is 25fps. That's not really right. Most NTSC content is either 60 fields per second with independent fields (video camera sourced) or 24 frames per second with 3:2 pulldown (film sourced). It's pretty rare to have content that's actually 30 frames per second broken into even and odd fields. Early video game systems ran essentially 60p @ half the lines; they would put out all even or all odd fields, so there wasn't interlacing. If you deinterlace 60i content with a lot of motion to 30p by just combining two adjacent fields, it typically looks awful, because each field is an independent sample. Works fine enough with low motion though. PAL is similar, although 24 fps films were often shown at 25 fps to avoid jitter of showing most frames as two fields but two frames per second as three fields. I think most people find 24 fps film motion acceptable (although classical film projection generally shows each frame two or three times, so it's 48/72 Hz with updates at 24 fps), but a lot of people can tell a difference between 'film look' and 'tv look' at 50/60 fields (or frames) per second.
bsjshshsb 7mo ago
I wonder how dogs get on with RGB presentation?
- xoxxala 7mo ago
  Dogs can see some colors, but not as many as humans. They have dichromatic vision, and see shades of gray, brown, yellow and blue. Red and green are particularly bad colors for them. We get blue tennis balls for our pups instead of green; but they aren’t the fetching kind so not sure if it helps.
  - qwertfisch 7mo ago
    Regular tennis balls are yellow, why not just use these? (And are there really green tennis balls?)

by thih9 7mo ago

ulfw 7mo ago

What does frame rate have to do with being able to recognise a creature? If I watch a video in 10fps it looks shite but I still recognise everything on screen

drysart 7mo ago
It's about being able to perceive it as a "living" moving creature and not something different. You can understand something below the perception threshold is supposed to be a creature because you both have a far more advanced brain and you've been exposed to such things your entire life so there's a learned component; but your dog may simply not be capable of making the leap in comprehending that something it doesn't see as living/moving is supposed to be representative of a creature at all. I've personally seen something adjacent to this in action, as I had a dog over the period of time where I transitioned from lower framerate displays to higher framerate displays. The dog was never all that interested in the lower framerate displays, but the higher framerate displays would clearly capture his attention to the point he'd start barking at it when there were dogs on screen. This is also pretty evident in simple popular culture. The myth that "dogs can't see 2D" where 2D was a standin for movies and often television was pervasive decades ago. So much so that (as an example) in the movie Turner and Hooch from 1989, Tom Hanks offhandedly makes a remark about how the dog isn't enjoying a movie because "dogs can't see 2D" and no further elaboration on it is needed or given; whereas today it's far more common to see content where dogs react to something being shown on a screen, and if you're under, say, 30 or so, you may not have ever even heard of "dogs can't see 2D".
- harrall 7mo ago
  But how can you tell if it was lack of recognition? I wouldn’t be interested in a 2 FPS video either — in fact I would probably avoid looking at it, whether I recognized the humans in it or not.
  - drysart 7mo ago
    I mean it's a dog so you can't exactly ask them; but this was a dog that would bark at every other dog. If he wasn't barking at Hooch because Hooch was only showing up at 24 FPS, then I'm inclined to think he didn't recognize Hooch as another dog.
maverwa 7mo ago
With CRTs I would think that the problem may be that they do not see a full picture at all. Because the full screen is never lit all at once? Don’t know how persistence of vision works in this case…
afiori 7mo ago
With Cathode ray TVs only a single pixel at a time is on, it relies on our eyes having bad enough temporal resolution, if you have Superspeed eyes you will see just a coloured line/pixel moving on screen
- kevincox 7mo ago
  That's not quite true. Only one pixel is being activated at a time but the phosphors continue to emit light for many pixels. In practice you get a handful of lines lit to varying degrees at at time. Maybe 1-2 lines quite brightly lit and then a trail of lines that are fading pretty significantly (but still emitting light). They yes, our persistence of vision fills in the rest to provide the appearance of a fully lit screen. This video has some great slow-mo of CRTs https://www.youtube.com/watch?v=3BJU2drrtCM&t=160s https://www.youtube.com/watch?v=3BJU2drrtCM&t=160s

__alexs 7mo ago

> While people have an image frame rate of around 15-20 images per second to make moving pictures appear seamless, This is just...wrong? Human vision is much fast and more sensitive than we give it credit for. e.g. Humans can discern PWM frequencies up to many thousands of Hz. https://www.youtube.com/watch?v=Sb_7uN7sfTw https://www.youtube.com/watch?v=Sb_7uN7sfTw

zacmps 7mo ago
Badly phrased but not wrong, this is the minimum frame rate for humans to perceive motion as supposed to a slide show of images. The maximum frame rate we can perceive is much higher, for regular video it's probably somewhere around 400-800.
- Gigachad 7mo ago
  Maximum depends on what it is you are seeing. If it’s a white screen with a single frame of black, you can see that at incredibly high frame rates. But if you took a 400fps and a 450fps video, I don’t think you would be able to pick which is which.
nandomrumber 7mo ago
NO YOU ARE! > make moving pictures appear seamless True enough. NTSC is 30fps, while PAL is 25fps. The overwhelming majority of people were happy enough to spend, what, billions on screens and displays capable of displaying motion picture in those formats. That there is evidence that most(?) people are able to sense high frequency PWM signals doesn’t make the claim that 15 to 20 frames per second is sufficient to make moving pictures appear seamless. I’ve walked in to rooms where the LED lighting looks fine to me, and the person I was with has stopped, said “nope” and turned around and walked out, because to them the PWM driver LED lighting makes the room look illuminated by night club strobe lighting. That doesn’t invalidate my experience.
- toast0 7mo ago
  > NTSC is 30fps, while PAL is 25fps. That's not really right. Most NTSC content is either 60 fields per second with independent fields (video camera sourced) or 24 frames per second with 3:2 pulldown (film sourced). It's pretty rare to have content that's actually 30 frames per second broken into even and odd fields. Early video game systems ran essentially 60p @ half the lines; they would put out all even or all odd fields, so there wasn't interlacing. If you deinterlace 60i content with a lot of motion to 30p by just combining two adjacent fields, it typically looks awful, because each field is an independent sample. Works fine enough with low motion though. PAL is similar, although 24 fps films were often shown at 25 fps to avoid jitter of showing most frames as two fields but two frames per second as three fields. I think most people find 24 fps film motion acceptable (although classical film projection generally shows each frame two or three times, so it's 48/72 Hz with updates at 24 fps), but a lot of people can tell a difference between 'film look' and 'tv look' at 50/60 fields (or frames) per second.

bsjshshsb 7mo ago

I wonder how dogs get on with RGB presentation?

xoxxala 7mo ago
Dogs can see some colors, but not as many as humans. They have dichromatic vision, and see shades of gray, brown, yellow and blue. Red and green are particularly bad colors for them. We get blue tennis balls for our pups instead of green; but they aren’t the fetching kind so not sure if it helps.
- qwertfisch 7mo ago
  Regular tennis balls are yellow, why not just use these? (And are there really green tennis balls?)