← Back to context

Comment by Laremere

5 days ago

I'd say it's better to call it a unit of counting.

If I have a bin of apples, and I say it's 5 apples wide, and 4 apples tall, then you'd say I have 20 apples, not 20 apples squared.

It's common to specify a length by a count of items passed along that length. Eg, a city block is a ~square on the ground bounded by roads. Yet if you're traveling in a city, you might say "I walked 5 blocks." This is a linguistic shortcut, skipping implied information. If you're trying to talk about both in a unclear context, additional words to clarify are required to sufficiently convey the information, that's just how language words.

Exactly. Pixels are indivisible quanta, not units of any kind of distance. Saying pixel^2 makes as much sense as counting the number of atoms on the surface of a metal and calling it atoms^2.

  • So how does subpixels come into play under this idea of quanta?

    • Pixels then become containers and subpixels become quantfiable entities within each pixel. In the apple analogy, each crate contains three countable apples and you can count both the crates and the apples independently.

      This idea itself breaks down when we get to triangular subpixel rendering, which spans pixels and divides subpixels. But it's also a minor form of optical illusion, so making sense of it is inherently fraught.

      Maybe a pixel is just a pixel.

    • Quarks? They’re sub-units of hadrons but iirc they can’t be found on their own.

    • they don't need to, you can have monochrome pixels too, like those on monochrome displays)

That is exactly how it is and it makes the whole article completely pointless. Especially as the article in the second sentence correctly writes "1920 pixels wide".

Is it that, or is it a compound unit that has a defined width and height already? Something can be five football fields long by two football fields wide, for an area of ten football fields.

  • This example illustrates potential confusion around non-square pixels. 5 football fields long makes perfect sense, but I'm not sure if 2 football fields wide means "twice the width of a football field" or "width equaling twice the length of a football field". I would lean towards the latter in colloquial usage, which means that the area is definitely not the same as the area of 10 football fields

    • I would lean towards the former. I really don't think people are trying to compare the width to the length when discussing football fields casually.

      If I told you parking spots are about two bowling lane's wide... I'm obviously not trying to say they are 120ft wide.

      1 reply →

  • No, it is a count. Pixels can have different sizes and shapes, just like apples. Technically football fields vary slightly too but not close to as much as apples or pixels.

    • Football fields also have the fun property of varying in the third dimension. They're built with a crown in the middle so that water will drain off towards the edges, and that can vary significantly between instances.

      And pixels are even starting to vary in the third dimension too, with the various curved and bendable and foldable displays.

      1 reply →

    • Pixel counts generally represent areas by taking the number of pixels inside a region of the plane, but they can represent lengths by taking the number of pixels inside a certain extent of a single line or column of the grid: it is, actually, a thin rectangle.

It think the point of the article is that you don't say "5 pixels wide x 4 pixels tall" but just "5 pixels x 4 pixels", though I would say that "5x4 pixels" is the most common and most correct terminology.

And the article concludes with : "But it does highlight that the common terminology is imperfect and breaks the regularity that scientists come to expect when working with physical units in calculations". Which matches your conclusion.

  • > And the article concludes with : "But it does highlight that the common terminology is imperfect and breaks the regularity that scientists come to expect when working with physical units in calculations". Which matches your conclusion.

    But it's not true. Counts (like "number of pixels" or "mole of atoms") are dimensionless, which is a precise scientific concept that perfectly matches the common terminology.

> If I have a bin of apples, and I say it's 5 apples wide, and 4 apples tall

...then you have a terrible bin for apple storage and should consider investing in a basket ;)