# Why are Pixels square? **URL:** \ **Category:** Factual Questions\ **Created:** [January 11, 2014, 10:50am UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505 "2014-01-11T10:50:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![randompattern](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@randompattern](https://boards.straightdope.com/u/randompattern)\ **Post date:** [January 11, 2014, 10:50am UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/1 "2014-01-11T10:50:54Z")
Could they be made in different shapes and sizes? Would this help with resolution and clarity when zooming? ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [January 11, 2014, 12:10pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/2 "2014-01-11T12:10:32Z")
Pixels aren’t square. Pixels are individual units. They have no inherent shape. An image is just an array of numbers. It might be something like this: 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 1 1 1 2 1 1 1 1 1 2 1 1 2 1 2 1 2 1 2 1 1 2 1 1 1 1 1 2 1 1 2 1 2 2 2 1 2 1 1 2 1 1 1 1 1 2 1 1 1 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 What is the shape of each individual number? There isn’t one. Now, if you were looking at this or editing it in some kind of image program, as you zoom in it’s probably going to render each individual unit as a square. That’s just because it needs to draw some kind of boundary between each pixel, and it’s easiest just to lay them out on a square grid. When the image gets sent to your monitor, it’s the same kind of thing. Each individual pixel unit gets displayed at a specific point on the screen. That “pixel” on your screen could be three individual color thingies (how’s that for a technical term) right next to each other, one for red, one for green, and one for blue. Those little parts might be square-ish, or they may be more rounded, depending on the construction of your monitor. If you look at a monitor screen very closely though, it’s not a grid of perfect squares with no space at all between them. It’s actually broken up into smaller discrete units. There’s no reason your rendering program couldn’t draw the individual pixels as little circles as you zoom in, but circles have space in between them. What do you do with that empty space? Or do you overlap the circles? Then what color do you use for the overlap? Squares are just easier. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [January 11, 2014, 12:11pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/3 "2014-01-11T12:11:47Z")
> [@randompattern](#): > > Could they be made in different shapes and sizes? Would this help with resolution and clarity when zooming? Best to not have any gaps between the pixels. Best to have the light produced equally across a large pixel than to have a tiny dot in the middle glowing really brightly. Also, for ease of the analog being displayed on a CRT… While the CRT had lines, the CRT doesn’t actually draw things pixel by pixel across the screen. It was the source that was flipping the signal from one colour to another… What that means is that there are no discrete pixels across the line… it was just a continuous waveform… I remember that at some modes the lines wouldn’t be totally jammed up next to each other, and there was small gap visible … it looked horrible ---
**Author:** ![randompattern](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@randompattern](https://boards.straightdope.com/u/randompattern)\ **Post date:** [January 11, 2014, 12:23pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/4 "2014-01-11T12:23:00Z")
What if it were a combination of shapes to fill in the gaps? Maybe circles combined with four pointed stars to fill in between? ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [January 11, 2014, 12:26pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/5 "2014-01-11T12:26:57Z")
Pixels ARE square, or at least rectangular and most often square or close to it. Conceptually they are points spread over an image to represent it, but in practice they are almost always spread in a rectangular array, and usually one with equal or nearly equal spacing on the two axes. And, often, the way they are filled out is an attempt to maximize illuminated or printed pixel area as a fraction of total area, which makes them square. And pixels don’t need to be square or, more particularly, arranged in a rectangular array. It would just be a lot more work to make them otherwise. But it would be better in some ways to go to the trouble of doing this. If they were arranged more like the stones in a typical stone wall, or like the patches of dried mud between cracks in what was the bottom of a now dried up lake, certain artifacts of rectangular pixel arrangements would go away. There would not be Moire patterns, and you would not see pronounced “jaggies” on lines that were slightly off of vertical and horizontal. Pixelization would not confound itself with vertical and horizontal details of the image. Who wants to design a video card for Penrose tile pixels? ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [January 11, 2014, 12:29pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/6 "2014-01-11T12:29:19Z")
There’s a neat, relevant Wikipedia article on “Tessellation”, which is the tiling of a plane with space filling shapes of one or more forms. ---
**Author:** ![Doughbag](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@Doughbag](https://boards.straightdope.com/u/Doughbag)\ **Post date:** [January 11, 2014, 12:51pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/7 "2014-01-11T12:51:26Z")
> [@randompattern](#): > > Could they be made in different shapes and sizes? Would this help with resolution and clarity when zooming? Each pixel can only have ONE colour, if you make it round, there will be “white” between them. For printers it’s round, but then called dpi (dots per inch). The more dots you have in the predefined area, the more details you have, since each dot is smaller – the area is defined and limited. Pixels are not defined by size, since they are a definition of what colour a specific area has. You can display a 100x100 pixel in an area of half an inch or 2 meters. Or let’s say a 1366x768 pixel screen can be 10.1”, 14.1”, 15.6”, 17.3” or 42”. The picture will look sharpest the smaller the screen is, since these 1049088 individual pixels are way smaller, since each individual pixel reproduction item (let’s say LED for a screen or bulb) is physically smaller. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 11, 2014, 1:07pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/8 "2014-01-11T13:07:09Z")
Other layouts of pixels have been tried (especially if you include the phosphor dot geometries of CRT displays - which, whilst not exactly pixels, are closely related enough to warrant discussion in the same topic). For example, the LCD display on the XO-1 One Laptop Per Child device were roughly diamond-shaped - although still laid out in a grid. > **[OLPC XO](https://en.wikipedia.org/wiki/OLPC_XO-1#Display_resolution)** > > The OLPC XO (formerly known as $100 Laptop, Children's Machine, 2B1) is a low cost laptop computer intended to be distributed to children in developing countries around the world, to provide them with access to knowledge, and opportunities to "explore, experiment and express themselves" (constructionist learning). The XO was developed by Nicholas Negroponte, a co-founder of MIT's Media Lab, and designed by Yves Behar's Fuseproject company. The laptop is manufactured by Quanta Co The subnotebooks ... And other displays (especially OLEDs) employ different layouts - such as PenTile: > **[PenTile matrix family](https://en.wikipedia.org/wiki/PenTile_matrix_family)** > > PenTile matrix is a family of patented subpixel matrix schemes used in electronic device displays. PenTile is a trademark of Samsung. PenTile matrices are used in AMOLED and LCD displays. > These subpixel layouts are specifically designed to operate with proprietary algorithms for subpixel rendering embedded in the display driver, allowing plug and play compatibility with conventional RGB (Red-Green-Blue) stripe panels. > "PenTile Matrix" (a neologism from penta-, meaning "five" in Greek and tile) ... ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [January 11, 2014, 1:38pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/9 "2014-01-11T13:38:10Z")
> [@randompattern](#): > > What if it were a combination of shapes to fill in the gaps? Maybe circles combined with four pointed stars to fill in between? This would be pointless and computationally very expensive. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [January 11, 2014, 2:53pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/10 "2014-01-11T14:53:05Z")
For the best display, they’d be hexagonal, but that would be computationally more expensive. Instead, they just keep making them smaller, and at this point it hardly matters what shape they are (e.g., on my 15" laptop screen that’s 1920x1080). ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [January 11, 2014, 2:55pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/11 "2014-01-11T14:55:31Z")
> [@Doughbag](#): > > Each pixel can only have ONE colour, if you make it round, there will be “white” between them. Only when printing (on white paper). On a (black) screen, there would be black between them. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 11, 2014, 3:02pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/12 "2014-01-11T15:02:11Z")
> [@randompattern](#): > > What if it were a combination of shapes to fill in the gaps? Maybe circles combined with four pointed stars to fill in between? > [@njtt](#): > > This would be pointless and computationally very expensive. It’s not a million miles different from the PenTile Matrix 2 detailed here: > **[Sharper Images](https://www.pcmag.com/archive/sharper-images-44534)** > > ClairVoyante offers a new approach to LCDs. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [January 11, 2014, 3:10pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/13 "2014-01-11T15:10:35Z")
> [@randompattern](#): > > What if it were a combination of shapes to fill in the gaps? Maybe circles combined with four pointed stars to fill in between? How about [Fuji Super CCD?](http://en.wikipedia.org/wiki/Super_CCD) ---
**Author:** ![Doughbag](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@Doughbag](https://boards.straightdope.com/u/Doughbag)\ **Post date:** [January 11, 2014, 4:41pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/14 "2014-01-11T16:41:22Z")
> [@Learjeff](#): > > Only when printing (on white paper). On a (black) screen, there would be black between them. That’s the reason I used theses “” marks, when I used the term “white”. Also when printing, it’s not pixels anymore - its dpi on the paper. You can print a single pixel in whatever size your printer can print. A pixels is ONE unit containing one single colour information, but is not defined by size. The size of the pixel is defined by the “displaying” unit. Within an image files pixel are square, but you can display ONE single image pixel over several display pixels on a screen, but each single pixel on a screen can only produce ONE single colour. What the form or build factor of your screen is another matter, see picture in the [link](http://www.outdoor-ledscreens.com/photo/pl394972-led_silk_series_real_led_screen_wallpaper_for_architectural_stage_concert_clubs_etc.jpg) – you can see individual pixels via pixilation with pixels, but the pixels of this LED screen are not square. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [January 11, 2014, 8:22pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/15 "2014-01-11T20:22:19Z")
> [@Mangetout](#): > > It’s not a million miles different from the PenTile Matrix 2 detailed here: > [Sharper Images | PCMag](http://www.pcmag.com/article2/0,2817,1189469,00.asp) That might be interesting if there were any explanation. Could they be trying to exploit the fact that our eyes can resolve blue less well than other colors? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 11, 2014, 8:31pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/16 "2014-01-11T20:31:13Z")
> [@njtt](#): > > That might be interesting if there were any explanation. Could they be trying to exploit the fact that our eyes can resolve blue less well than other colors? There’s a bit more explanation [here](http://en.wikipedia.org/wiki/Subpixel_rendering#Non-striped_variants_of_the_RBG-GBR_alternated_layout). I think what they’re trying to achieve is the possibility of subpixel rendering that works in both horizontal and vertical directions (current subpixel rendering on LCD screens - e.g. Windows ClearType only improves the horizontal resolution) ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [January 11, 2014, 10:35pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/17 "2014-01-11T22:35:19Z")
> [@Learjeff](#): > > For the best display, they’d be hexagonal, but that would be computationally more expensive. I knew a guy who worked on a R&D project with a small company to develop exactly this – CRT or similar display, with pixels in a hexagonal grid. That was several years ago. Last I heard (I think), the company was getting into other things, and I guess the hexagonal project never came to anything. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [January 11, 2014, 11:51pm UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/18 "2014-01-11T23:51:09Z")
> [@njtt](#): > > That might be interesting if there were any explanation. Could they be trying to exploit the fact that our eyes can resolve blue less well than other colors? That’s [exactly what the Wikipedia page says](http://en.wikipedia.org/wiki/PenTile_matrix_family), so yes, that’s at least what they _claim_. I don’t think the ratios are optimized for our retina, though. CRTs used two main technologies: [aperture grille](http://en.wikipedia.org/wiki/Aperture_grille) and [shadow mask](http://en.wikipedia.org/wiki/Shadow_mask). Side note: Wikipedia has a [picture](http://upload.wikimedia.org/wikipedia/commons/b/b4/Trinitron.jpg) of the aperture grille Trinitron TV that I used to play NES on. I had completely forgotten about it. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 12, 2014, 4:59am UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/19 "2014-01-12T04:59:13Z")
Even if a hex grid (or a triangular grid or Penrose grid or whatever) were actually proven to be optimal, it’d still have to contend with the fact that we’ve got a whole lot of computational infrastructure already invested in rectangular pixels (like, for instance, every image format ever). If you wanted to move to some other grid, you’d have to either replace all of that, or come up with some efficient way of converting everything on the fly. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [January 12, 2014, 5:13am UTC](https://boards.straightdope.com/t/why-are-pixels-square/678505/20 "2014-01-12T05:13:42Z")
I thought PenTile was solely to compensate for green or blue sub-pixels in OLEDs not lasting as long, so they put more of those in? You COULD make pixels of different shapes, but they don’t because it’s just cheaper to make them smaller instead. [Next page](https://boards.straightdope.com/t/why-are-pixels-square/678505.md?page=2)