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Why are names like "High-DPI" used? There was a time when 320x200 graphics with 256 colors was amazing. Would 800x600 have been considered "high DPI" back then

Why are names like "High-DPI" used? There was a time when 320x200 graphics with 256 colors was amazing. Would 800x600 have been considered "high DPI" back then? Or in the time were people were playing Duke Nukem 3D at 640x480 pixels, would they have considered 1920x1280 to be "high DPI"? Windows has transitioned all the way from 640x480 in Windows 3.11 to the resolutions of today, why would there be a problem with just another step up? What is "high" DPI today? What will it be tomorrow?

thornjm 13y ago
Perhaps because we reaching a point where our eyes can longer perceive the individual pixels that we really have reached maximum resolution. Is there any benefit from higher resolution displays?
- mas644 13y ago
  there will always be those hardcore "videophiles" that will claim they can see the pixels even at a nanoscale ;)
- snogglethorpe 13y ago
  One advantage of high-density displays you sometimes see mentioned is that "we won't need to use anti-aliasing / sub-pixel rendering!" However at the common "high" density used in cellphones these days, 320+ DPI or so, artifacts in non-AA fonts are still visible (not always, or to everybody, but sometimes anyway). So, at least, there are some cases where higher-density than today could yield some benefit.
  - jbverschoor 13y ago
    I've turned off subpixel anti aliasing on my macbook pro retina. Net step would indeed be disabling anti aliasing
- rayiner 13y ago
  The ~235 ppi of the Retina display probably isn't there yet. The human eye is really a nifty organ. For example, it increases the spatial resolution of perception above the density of the rods/cones by sampling from slightly different viewpoints and integrating over time. See: http://clarkvision.com/articles/eye-resolution.html http://clarkvision.com/articles/eye-resolution.html. Also, there is the fact that you can move your face closer to the screen to look at something small. The eye can resolve over 800 ppi at 4". Finally, the fact that the eye can resolve say 300 ppi at a particular distance doesn't mean that's the best resolution for the underlying screen. If you want to render without tricks like anti-aliasing, you want to have enough resolution so that you avoid visible artifacts. E.g. imagine rendering two adjacent thin diagonal lines separated by 0.3 arc-minutes (the spatial resolution of the eye). You want enough resolution so that you can render those lines without their touching anywhere.
joosters 13y ago
Search & read some articles on 'retina' DPI. Sure, no-one can agree quite on what point DPI becomes so high that we can't notice further improvements, but the issue is that recently, displays are suddenly getting very near to that level.
captainmuon 13y ago
I guess it makes sense to talk about "High DPI", because there is a kind of barrier. "Resolutions" or more precisely pixel counts kept getting higher and higher for years, until they stagnated at 1920x1080. Display vendors couldn't go higher, because consumers would complain that "everything is too small". The reason is that the majority of software plays like it's still 1995 and you have 640x480 pixels. Everything is a fixed pixel size, not a fixed physical size. I'd say that all displays with a resolution (here I mean dpi) so high that its uncomfortable to use with current desktop programs are "High-DPI". Once the software is changed to allow arbitrary dpi scaling, there will be no barrier, so there is no low or high dpi anymore, just higher dpi. (And ultimatively, as soon as you can't see individual dots anymore, it won't make sense to increase the dpi further.)
- zanny 13y ago
  Also consider the limits of human vision. For most people, at a half meter viewing distance, something around 300 PPI is the limit of perception for most people. At a meter (where most people view the 27 - 30" big screens) it drops lower than that, probably to 200 PPI. Eventually it doesn't make sense to make denser panels because you don't see the difference anymore. This next generation of displays definitely isn't there yet, but it is "high" as in "we're getting there". I personally can't wait until we cap out pixel density, because then we can get variable refresh rate and color accuracy back. I want my 300 PPI vbr up to 120hz 10 bit color panel monitor for $300!
redial 13y ago
I think you are confusing high resolution with high DPI (Dots Per Inch). The first one is a measure of resolution while the second one a measure of density. Sure they are both related, and I think your point gets across, but they are not the same.
rsynnott 13y ago
'HiDPI' turned up as a MacOS term for a mode where physical resolution is higher than logical resolution. "High DPI" just means higher than 'normal' dots per inch. The terms are often used almost interchangeably.
Too 13y ago
Draw a character in as few pixels as possible. You will probably end up at 8-10px height. 6 or 7 is possible but looks like shit. Make a display with as high resolution that it becomes totally unfeasible to read this character without a magnifying glass. Then you have reached "high" DPI. The transitioning all the way down from 320x200 to today was possible because the same character was always readable, even though it previously covered half of the screen.

thornjm 13y ago

Perhaps because we reaching a point where our eyes can longer perceive the individual pixels that we really have reached maximum resolution. Is there any benefit from higher resolution displays?

mas644 13y ago
there will always be those hardcore "videophiles" that will claim they can see the pixels even at a nanoscale ;)
snogglethorpe 13y ago
One advantage of high-density displays you sometimes see mentioned is that "we won't need to use anti-aliasing / sub-pixel rendering!" However at the common "high" density used in cellphones these days, 320+ DPI or so, artifacts in non-AA fonts are still visible (not always, or to everybody, but sometimes anyway). So, at least, there are some cases where higher-density than today could yield some benefit.
- jbverschoor 13y ago
  I've turned off subpixel anti aliasing on my macbook pro retina. Net step would indeed be disabling anti aliasing
rayiner 13y ago
The ~235 ppi of the Retina display probably isn't there yet. The human eye is really a nifty organ. For example, it increases the spatial resolution of perception above the density of the rods/cones by sampling from slightly different viewpoints and integrating over time. See: http://clarkvision.com/articles/eye-resolution.html http://clarkvision.com/articles/eye-resolution.html. Also, there is the fact that you can move your face closer to the screen to look at something small. The eye can resolve over 800 ppi at 4". Finally, the fact that the eye can resolve say 300 ppi at a particular distance doesn't mean that's the best resolution for the underlying screen. If you want to render without tricks like anti-aliasing, you want to have enough resolution so that you avoid visible artifacts. E.g. imagine rendering two adjacent thin diagonal lines separated by 0.3 arc-minutes (the spatial resolution of the eye). You want enough resolution so that you can render those lines without their touching anywhere.

joosters 13y ago

Search & read some articles on 'retina' DPI. Sure, no-one can agree quite on what point DPI becomes so high that we can't notice further improvements, but the issue is that recently, displays are suddenly getting very near to that level.

captainmuon 13y ago

I guess it makes sense to talk about "High DPI", because there is a kind of barrier. "Resolutions" or more precisely pixel counts kept getting higher and higher for years, until they stagnated at 1920x1080. Display vendors couldn't go higher, because consumers would complain that "everything is too small". The reason is that the majority of software plays like it's still 1995 and you have 640x480 pixels. Everything is a fixed pixel size, not a fixed physical size. I'd say that all displays with a resolution (here I mean dpi) so high that its uncomfortable to use with current desktop programs are "High-DPI". Once the software is changed to allow arbitrary dpi scaling, there will be no barrier, so there is no low or high dpi anymore, just higher dpi. (And ultimatively, as soon as you can't see individual dots anymore, it won't make sense to increase the dpi further.)

zanny 13y ago
Also consider the limits of human vision. For most people, at a half meter viewing distance, something around 300 PPI is the limit of perception for most people. At a meter (where most people view the 27 - 30" big screens) it drops lower than that, probably to 200 PPI. Eventually it doesn't make sense to make denser panels because you don't see the difference anymore. This next generation of displays definitely isn't there yet, but it is "high" as in "we're getting there". I personally can't wait until we cap out pixel density, because then we can get variable refresh rate and color accuracy back. I want my 300 PPI vbr up to 120hz 10 bit color panel monitor for $300!

redial 13y ago

I think you are confusing high resolution with high DPI (Dots Per Inch). The first one is a measure of resolution while the second one a measure of density. Sure they are both related, and I think your point gets across, but they are not the same.

rsynnott 13y ago

'HiDPI' turned up as a MacOS term for a mode where physical resolution is higher than logical resolution. "High DPI" just means higher than 'normal' dots per inch. The terms are often used almost interchangeably.

Too 13y ago

Draw a character in as few pixels as possible. You will probably end up at 8-10px height. 6 or 7 is possible but looks like shit. Make a display with as high resolution that it becomes totally unfeasible to read this character without a magnifying glass. Then you have reached "high" DPI. The transitioning all the way down from 320x200 to today was possible because the same character was always readable, even though it previously covered half of the screen.