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naive question. Is there an arabic equiv of a 7 segment display? It looks like a writing system that is very amenable to that sort of digitization. Always a center line, and then up to two strokes going {up, down, diagonal, curved} intersecting at the {left, middle right} of the main line, followed by some dots to further specify a sub-category. Seems like a small finite set of graphical components being composed together. Which in fairness describes any writing system, but this one seems to have a very simple and predictable stroke sub-alphabet (I mean that as high praise not as a slight, simplicity is good). Am I wrong? What does a simple Arabic digital display look like? I've never seen one.

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us patent 4647924 (1987)

https://patentimages.storage.googleapis.com/a5/dc/27/34d036c...

Numbers will typically be rendered in Arabic numerals and not in Arabic script if a 7 segment display is being used. Latin characters are already pretty difficult to read on a 7 segment... Arabic would be even more difficult.

That's not entirely what I meant by my question. Let me try rephrasing. Is there a thing that works on the same principle as a 7 segment display, possibly with a more than 7 segments but still a manageable amount, which is designed to display Arabic characters with a similar amount of legibility?

I'm not an expert but I have gone down both the Arabic font creation road and the custom segmented display roads - not at the same time, of course.

My understanding of Arabic is that this would be _exceedingly_ hard to generalize into individual, discrete glyphs that could not only be broken out into their own segments but then repeated in a way that makes sense.

The only way I could personally think of is with matrix displays, which act more like normal displays.

This is because even though it is an alphabetic script, the blending between characters is non-trivial and highly dependent on the sequence of glyphs, which causes an explosion of possible combinations depending on what's being written.

That said, you can always design segmented displays that show _any_ shape or script, assuming you don't need to change them.

What exactly are the character blending rules? When you say non-trivial, are we talking normal non-trivial or oops-I-embedded-a-Turing-machine-in-my-written-language non-trivial?

I'm going to guess the various shifts you allude to are simple transformations for a pen-plotter, perhaps accumulating some "context" offsets to the initial position or flipping some glyph etc. Not sure how to translate that to segments, unless you can electro-mechanically adjust the segments...?...

Truetype fonts are more like polygonal vector graphics, less like lines/thicknesses. You generally combine two or more characters into a single glyph via a ligature.

But it doesn't end there. Fonts have a crazy number of different lookup tables that can affect how glyphs are drawn. While not Turing complete they're certainly very close.

In Arabic, how the baseline blends affecting the base shape of the glyph, plus lots of kerning rules, etc. would make Arabic very difficult to replicate on a segmented display.

I've never seen anything like that. But I have seen dot matrix displays render Arabic script

> Is there an arabic equiv of a 7 segment display?

A 7 segment display would have nowhere close to enough resolution to properly render Arabic script. Digital signage would at least be using a low-resolution LED matrix but more likely you'd see LED/LCD displays in places that are affluent and plain analog signage where they are not.

I could understand if this were a non-alphabet system like Chinese where the information coding is that dense per character. But for an alphabet system, why the mismatch between the bits of information per character and the bits needed to visually represent that character? The Latin alphabet mostly fits on a 7 seg display, and 26 letters requires a theoretical minimum of 5 bits to encode, so the graphical efficiency is close to optimal. What is it about the way other alphabets are encoding information that makes them hard or impossible to reduce down to a small number of segments?

Because the information coding is dense. Arabic script has a lot of tiny shapes that indicate what letter it is and it also has diacritic marks, which on their own are similarly intricate and small. You can't represent one line, two lines, a dot, a circle, a hamza, etc. above, below, to the side of particular characters, without a lot of resolution.

Another challenge for representing Arabic a display made of line segments is all the curves. If it weren't for the dots, I imagine you could write consonant-only Arabic on something close to a seven-segment display, although it would look bizarre because all the letters would be isolated and there would be so many more straight line segments than in normal Arabic script. (An absolute majority of the isolated forms of Arabic letters are made up only of curves, whereas an absolute majority of Latin capital letters are made up only of straight line segments!)

I wonder how Arabic ended up with characters that differ only by dot positioning (like ب ت ث, and also ن whose combining form is especially similar to the combining forms of those). By contrast, the most similar Latin characters might be EF / CG / IJ / MN / UV which I think are clearly more different than the Arabic characters that differ only by dot quantity and positioning.

(The Il1| are also famously confusable in some Latin fonts, but one could say having to worry about these comes late in the history of Latin script writing. Although the scribal minim https://en.wikipedia.org/wiki/Minim_(palaeography) used at some points to write u, i, m, and n is every bit as confusing as any Arabic character.)

I don't think curves are a technological problem for a segmented display. You can easily make curved segments and dots. Its all just an LED behind a window painted over with the negative image of the curve. In principle you could make a display that is optimized for OCGDU rather than EIFHTL.

Much like latin characters, at some point a segmented display is just going to have to compromise on the tradeoff between correct an the number of parts. We see it work just fine casting the curvy latin letters to squares. So the real question I reckon is how much can you mangle the diacritics / curves / other parts and still read it? In other words, what is the bandwidth redundancy of this writing system?

Yes, I wasn't thinking flexibly enough there (no pun intended). Interesting questions!

hold up. Representing a line, two lines, a dot, a circle... in one of several fixed positions relative to the character...that's exactly what a segmented display is good at. I think you may not have got what I meant by "dense". I'm looking at it from a pure information theoretic view. There's something like 5000 Chinese characters overall. Even if I could find a system of on/off segments to represent them all, I would still have to use at least 13 segments, because it takes at least 13 bits to encode 5000 possibilities. Chinese is dense in the sense that a whole 13 bits have to fit in the space of a single character. Granted diacrtics and other markers do add one or two new bits, but adding permutations isn't the same as adding complexity. Every time you learn one diacritic, you've doubled the number of letters you know how to write. Whereas in Chinese, when you learn a new character, you've learned a new character.

Other commenter nailed the real technical hurdle. Context dependent spacing system. How do monotypes do it (or do those not exist)?

There's certainly a finite set of combinations but in order for you to create a segmented display that isn't just a dot matrix, you need to have few enough variations that it can 1) actually encode all of the characters and their context-specific variations, 2) have segments that at least somewhat resemble the characters they are supposed to represent and 3) if they are overlapping must be able to to render all of the components of every letter distinctly. So If you have a line that you also want to be two or three dots and a hamza or some other diacritic, you need to break each segment down to the lowest common denominators.

A 7-segment display works by turning on and off each of the segments in order to render a glyph that is supposed to represent English alphanumeric characters. It mostly accomplishes this, though just barely and honestly a lot of characters do not render well at all (like the lowercase "i"). How would you shape the segments in such a way that could accomplish at least that level of clarity in Arabic?

I personally think that what you'd end up with would very closely resemble a dot matrix.

never seen one. my guess is it does not exist. it would make a great artistic project

based on the time stamp, you spoke almost exactly too soon. See alphabet9000s reply above yours.

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