6 ms·

The reason you can only do this with video is to avoid burn in?

by Snoozus 3y ago

progbits 3y ago
No standardized support in HTML/CSS. Video containers can store the color profile information.
- cubefox 3y ago
  I assume CSS colors are defined for an sRGB color space and the iPhone displays are calibrated, so they show a smaller color range than they could. OLED is able to go well beyond sRGB.
  - zokier 3y ago
    CSS color() can do Display-P3 and Rec2020
  - adrian_b 3y ago
    Not only OLED, but most good LCD monitors support the Display P3 color space (derived from DCI P3), with 30 bit per pixel, which is much larger than sRGB. While Safari has been supporting Display P3 for several years, all major browsers support since the beginning of the year CSS Color Module Level 4, which includes support for Display P3 (for all the other even larger supported color spaces there are no monitors or TV sets of reasonable price that can display them). Most monitors come from the factory configured to display 24-bit sRGB colors, so the user must change the default settings to be able to display 30-bit Display P3 colors. However the color space only affects the maximum saturation of the colors, not the maximum brightness of the colors, which is determined by the brightness setting of the monitor. For a white brighter than the brightest normal white, it is not enough to have a monitor with a wide color gamut, it must also be HDR capable and the software must support HDR too.
    - cubefox 3y ago
      I don't quite get the saturation/brightness difference here. Isn't $fff "whiter" than $eee? Where whiter means brighter? Then why couldn't the whitest color be even whiter, and hence brighter, in a larger color space? (I assume the answer is that a larger color space contains colors that are "redder" or "yellower", but not "whiter", for some reason.)
      - adrian_b 3y ago
        A color is determined by 3 numbers, when those 3 numbers are chosen to be hue, saturation and brightness, that means that this color cannot be distinguished from a mixture of monochromatic light with a standard kind of white light (e.g. D65), both lights having certain radiant powers (per solid angle and/or per area). In that case, the hue is the frequency or wavelength of the monochromatic light, the saturation is the ratio between the (weighted by the eye sensitivity curve) radiant powers of the monochromatic light and of the total light (so a completely saturated color is monochromatic, without any added white), while the brightness is the total radiant power (weighted by the eye sensitivity curve). The red, green and blue pixel components of a display do not emit monochromatic light, unless the display is a laser projector. For any non-laser display the light emitted by a pixel component is equivalent with a mixture of a completely saturated color of the same hue with white light. This is especially obvious in the red of a sRGB display, which is much less saturated than a color that could be accepted as pure red. When two red colors have the same hue, the more saturated color is "redder", as it has less white and more red. "Redder" is ambiguous as it can be also used when comparing colors of the same saturation and brightness but of different hues, e.g. when comparing two reddish oranges, where the redder has more red and less green, or when comparing two reddish purples, where the redder has more red and less blue. Any color display can show any color hue, the difference between the displayed color spaces is only in the maximum displayed saturation, which cannot exceed the saturation of the individual R, G and B pixel components. When you specify RGB colors, you specify only relative values, i.e. by ratios vs. the RGB components of the brightest white light that the monitor has been configured to emit through its "brightness" setting. For instance, on a certain monitor setting the "brightness" to "75%" might mean that the brightest white has a luminance of 100 cd/m^2, while on another monitor model the same "75%" might correspond to a very different luminance of white, but in any case changing the setting will increase or decrease the brightness of all displayed colors, without changing their hues or saturations. Both "#f0f0f0" and "#e0e0e0" are white and normally one would say that the former is brighter than the latter. If on the axis of black to white one labels as "white" the brightest white and as "gray" the white of half brightness, then one may say that the former is "whiter" than the latter. However this usage is not recommended, because it is ambiguous. It is much more common to say that a color is "whiter" with the intention to say that it is less saturated, i.e. it is a mixture of more white with less of a monochromatic color, than to use "white" as a synonym of "bright".
- deleted 3y ago
  [deleted]
elvisds 3y ago
This was explained in demo website [1] that was submitted earlier today [2] > It works by displaying a color whose brightness is way outside the standard range of sRGB color space. > Unfortunately, this color cannot be represented with CSS colors (rgb(999,999,999) doesn’t work) or any of the widely-supported image formats. However, an HDR video can represent this color. [1] https://notes.dt.in.th/HDRQRCode https://notes.dt.in.th/HDRQRCode [2] https://news.ycombinator.com/item?id=36384625 https://news.ycombinator.com/item?id=36384625
- jojobas 3y ago
  Using any monitor in a room with a window on a sunny day you'll want to ramp up brightness way above the sRGB-mandated 80cd/sqm. True sRGB colours only make sense for print designers anyway, anybody else adjusts their white brightness as needed. This is a gimmick and Apple's usual pioneering stunt.
- Jasper_ 3y ago
  In theory, you could do this with the rec2020 color space included in CSS Color 4. https://www.w3.org/TR/css-color-4/#predefined-display-p3 https://www.w3.org/TR/css-color-4/#predefined-display-p3

The reason you can only do this with video is to avoid burn in?

progbits 3y ago

No standardized support in HTML/CSS. Video containers can store the color profile information.

cubefox 3y ago
I assume CSS colors are defined for an sRGB color space and the iPhone displays are calibrated, so they show a smaller color range than they could. OLED is able to go well beyond sRGB.
- zokier 3y ago
  CSS color() can do Display-P3 and Rec2020
- adrian_b 3y ago
  Not only OLED, but most good LCD monitors support the Display P3 color space (derived from DCI P3), with 30 bit per pixel, which is much larger than sRGB. While Safari has been supporting Display P3 for several years, all major browsers support since the beginning of the year CSS Color Module Level 4, which includes support for Display P3 (for all the other even larger supported color spaces there are no monitors or TV sets of reasonable price that can display them). Most monitors come from the factory configured to display 24-bit sRGB colors, so the user must change the default settings to be able to display 30-bit Display P3 colors. However the color space only affects the maximum saturation of the colors, not the maximum brightness of the colors, which is determined by the brightness setting of the monitor. For a white brighter than the brightest normal white, it is not enough to have a monitor with a wide color gamut, it must also be HDR capable and the software must support HDR too.
  - cubefox 3y ago
    I don't quite get the saturation/brightness difference here. Isn't $fff "whiter" than $eee? Where whiter means brighter? Then why couldn't the whitest color be even whiter, and hence brighter, in a larger color space? (I assume the answer is that a larger color space contains colors that are "redder" or "yellower", but not "whiter", for some reason.)
    - adrian_b 3y ago
      A color is determined by 3 numbers, when those 3 numbers are chosen to be hue, saturation and brightness, that means that this color cannot be distinguished from a mixture of monochromatic light with a standard kind of white light (e.g. D65), both lights having certain radiant powers (per solid angle and/or per area). In that case, the hue is the frequency or wavelength of the monochromatic light, the saturation is the ratio between the (weighted by the eye sensitivity curve) radiant powers of the monochromatic light and of the total light (so a completely saturated color is monochromatic, without any added white), while the brightness is the total radiant power (weighted by the eye sensitivity curve). The red, green and blue pixel components of a display do not emit monochromatic light, unless the display is a laser projector. For any non-laser display the light emitted by a pixel component is equivalent with a mixture of a completely saturated color of the same hue with white light. This is especially obvious in the red of a sRGB display, which is much less saturated than a color that could be accepted as pure red. When two red colors have the same hue, the more saturated color is "redder", as it has less white and more red. "Redder" is ambiguous as it can be also used when comparing colors of the same saturation and brightness but of different hues, e.g. when comparing two reddish oranges, where the redder has more red and less green, or when comparing two reddish purples, where the redder has more red and less blue. Any color display can show any color hue, the difference between the displayed color spaces is only in the maximum displayed saturation, which cannot exceed the saturation of the individual R, G and B pixel components. When you specify RGB colors, you specify only relative values, i.e. by ratios vs. the RGB components of the brightest white light that the monitor has been configured to emit through its "brightness" setting. For instance, on a certain monitor setting the "brightness" to "75%" might mean that the brightest white has a luminance of 100 cd/m^2, while on another monitor model the same "75%" might correspond to a very different luminance of white, but in any case changing the setting will increase or decrease the brightness of all displayed colors, without changing their hues or saturations. Both "#f0f0f0" and "#e0e0e0" are white and normally one would say that the former is brighter than the latter. If on the axis of black to white one labels as "white" the brightest white and as "gray" the white of half brightness, then one may say that the former is "whiter" than the latter. However this usage is not recommended, because it is ambiguous. It is much more common to say that a color is "whiter" with the intention to say that it is less saturated, i.e. it is a mixture of more white with less of a monochromatic color, than to use "white" as a synonym of "bright".
deleted 3y ago
[deleted]

elvisds 3y ago

This was explained in demo website [1] that was submitted earlier today [2] > It works by displaying a color whose brightness is way outside the standard range of sRGB color space. > Unfortunately, this color cannot be represented with CSS colors (rgb(999,999,999) doesn’t work) or any of the widely-supported image formats. However, an HDR video can represent this color. [1] https://notes.dt.in.th/HDRQRCode https://notes.dt.in.th/HDRQRCode [2] https://news.ycombinator.com/item?id=36384625 https://news.ycombinator.com/item?id=36384625

jojobas 3y ago
Using any monitor in a room with a window on a sunny day you'll want to ramp up brightness way above the sRGB-mandated 80cd/sqm. True sRGB colours only make sense for print designers anyway, anybody else adjusts their white brightness as needed. This is a gimmick and Apple's usual pioneering stunt.
Jasper_ 3y ago
In theory, you could do this with the rec2020 color space included in CSS Color 4. https://www.w3.org/TR/css-color-4/#predefined-display-p3 https://www.w3.org/TR/css-color-4/#predefined-display-p3