Does low resolution video look better on high PPI display?

Discussion in 'Computer Hardware, Devices and Accessories' started by JFTS, Jan 7, 2016.

  1. JFTS
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    JFTS GBAtemp Regular

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    I have a few old PAL VCDs that I am toying with and of course they don't look all that good on my 1280x1024 monitor. However, I copied the mpeg .DAT file (no conversion) and transferred it on a Samsung Galaxy Core Plus smartphone where I played it with VLC and I noticed it's a little bit sharper on its native resolution of 352x288.

    Was it because my eyes were closer to the screen? Can this actually "improve" the viewing quality or it is just my imagination? I'm asking more generally here. Can a high PPI display impove a low resolution video or will it only look tinier?

    Well, is there anyone who can reply or direct me to an appropriate source of information?
     
    Last edited by JFTS, Jan 7, 2016
  2. FAST6191

    FAST6191 Techromancer

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    Greater pixel density, especially when coupled with a smaller screen, can change how things play out. Before that though a quick search says 480 x 800 pixels for the phone screen in question ( http://www.gsmarena.com/samsung_galaxy_core_plus-5842.php ) which is a considerably smaller scale to do than to 1024 vertical res. In neither case are you likely to be getting more detail (such things can be done but not in real time) but I have noticed that scaling artifacts are more noticeable to people than simple lack of clarity.

    Equally are you sure you did not have different playback filters between the PC and the phone?
     
  3. JFTS
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    JFTS GBAtemp Regular

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    I'm sure there were no filters. Just default VLC playing.

    Could you elaborate a bit more on this topic? I am trying to understand if there is a difference in perception of such videos in a high PPI display that makes the content look "better".

    In the same manner, what would be the best way to display these low resolution videos?
     
  4. FAST6191

    FAST6191 Techromancer

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    Best. Get better masters -- much of what I am to cover is great but in the end it could probably all fall under "lipstick on a pig", especially for source material as low as VCD. That is probably not going to happen here though but I do have to say it. If these are old home videos that someone converted to VCD in the 90s then try to find the original films and whatnot.
    Better. Rerender with some of the crazy scaling algorithms -- there are scaling algorithms out there that do wonders that would not work in real time on any machine you will buy in the next 10 years. VLC and whatever else just use the standard filters we have had for years (bilinear, bicubic, lanczos and such), it is old but here is a basic test people like to see http://www.general-cathexis.com/interpolation/ and you can also have a really crazy filter http://bengal.missouri.edu/~kes25c/t0.png . Couple that with some for the better filters out there for motion based interpolation and you can get good stuff for your 30 hour render. If you are really bored you can manually remaster things and go scene by scene/frame by frame but that is horribly tedious.
    Not as good. Play with something like http://madvr.com/ , it will try some of the more CPU killer scaling and filtering if you ask it to that VLC will not try.
    After this we are back in normal things you might have already seen.

    High ppi can hide some issues, or conversely trouble things (I am writing this on a 27 inch 1080p monitor some 450mm from my face -- I can see pixels if I try), however I would place good money on any major improvements in this case being that the phone screen is low resolution and small.
     
  5. JFTS
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    JFTS GBAtemp Regular

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    Thanks for the information. I will check these programs.

    I have two more questions, however. Suppose we have a screen with a resolution of 352x288 exactly, both in pixels and in actual size (inches). Would a video with the same resolution look better on it than on a screen of the same size but much higher resolution, namely higher PPI?

    And finally, what if I could project a 352x288 video on a something like a cinema projector. Is it possible to magnify it as much as you want or you have to have your video above a standard resolution to be projected clearly?
     
  6. Originality

    Originality Chibi-neko

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    I haven't researched the topic much, but from what I've heard having greater pixel density only improves picture clarity up to a certain point, and that point is determined by your distance to the screen.

    It's like how some tech shows did a song and dance about squeezing 4K into a smartphone screen, yet reviewers said they the only started to see the difference when the screen was just a few inches from their face. The only practical use for such high pixel density is in VR goggles. The further the screen is from your face, the lower the pixel density threshold is before pixels blur together in your eyes and you lose the definition. Like with 4K TVs that are around the 40" mark, if you're more than 2-3 metres away from the screen, you might as well just have a 1080p TV because your eyes can't tell the difference. And if you're around 4-5 metres away from the screen, you might as well have a 720p TV for the same reason.
     
    Last edited by Originality, Jan 10, 2016 - Reason: spelling, damned autocorrect...
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  7. FAST6191

    FAST6191 Techromancer

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    As Originality said the human eye (and some are better than others -- 20/20 vision is not as good as it gets) can only resolve so much detail.

    Higher ppi/resolution... In microscopy there is a concept called empty magnification which is where you increase the magnification but can not see anything extra/resolve anything extra*, you are considering something like it here but for video. You will probably also be running into the concept of lossy encoding errors, I already mentioned that you might see macro blocks more on a larger screen. A further complication will come from what the difference is -- there is a reason you are encouraged to increase resolution but a given number of times rather than a fractional amount (288 to 400 is a fractional multiple, 576 on the other hand is 2 times). Going even further I suppose I could bring in concepts like those normally seen on fonts (things like sub pixel rendering, http://www.joelonsoftware.com/items/2007/06/12.html for a nice overview of it all) if you are considering some of the motion based interpolation -- if you are on a 288 high screen then you can move one pixel but if your motion reckons the actual movement is a quarter of a pixel in the original source it can't do much, however if you are on an 1152 screen (288x4) it can display this change. Motion is the high end but even a bit of softening or filters that can be done in real time

    *pro tip in this case is never ask what magnification a microscope is, unless you know what magnification means for a microscope/microscope component and actually want to know that, and instead ask what resolution it can achieve/what it can resolve.

    Shorter version -- you might have seen too much CSI, or there is a reason "zoom and enhance" is a joke
     
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  8. JFTS
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    JFTS GBAtemp Regular

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    Thank both of you for your detailed answers. My questions sound a bit naive, but that is because I don't know the appropriate terminology. Now I can research better.
     
  9. Lycanroc

    Lycanroc Midnight Wolf

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    I don't really know if this answers your question, but I noticed something recently. When I play a 320p video on my computer's 1080p monitor, I notice obvious giant pixels, I could literally count them if I wanted to. But if I play that same video on my 480p CRT TV (which has about the same diagonal as my PC's monitor), it looks much sharper and more watchable.
     
  10. JFTS
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    JFTS GBAtemp Regular

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    It's because these low resolutions were made for CRT displays. The same thing applies for older consoles too.
     
  11. FAST6191

    FAST6191 Techromancer

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  12. JFTS
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    JFTS GBAtemp Regular

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    Interesting. Does the same apply for CRT PC monitors also?
     
  13. FAST6191

    FAST6191 Techromancer

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    Sometimes the quality controls were a bit tighter (and sometimes not) and the increased resolution can lessen some of those effects but yeah it does.