What's with ligatures.

[DaleDe]

Originally Posted by pdurrant

Yes. The rendering engines could do with a lot of improvements, especially as displays get to be higher resolution. The Mirasol display is going to be about 225 dpi or so. We can't be many years off a high quality 300dpi paper-like display.

I do not believe display resolution has anything to do with ligature use. The purpose of ligatures are to improve the character spacing visually when the smallest space was a point size (only 72 dpi). They really wouldn't be needed at all if the resolution was high enough to adjust the spacing on a character by character basis. Of course the actual outline shape might look a little better with high resolution but this is not a ligature issue and anti-aliasing techniques pretty much take care of this anyway.

I do believe that the source eBooks should never use ligatures. Ligatures should be added by the rendering engine as one method among others to improve character tracking. EBooks should be sources and not attempt to force rendering, fix tracking, etc. You can read about typography in our wiki.

Dale

[frabjous]

Originally Posted by delphidb96

The biggest problem with ligatures - in general - is that their use presumes: a) the reader's eyes are not SHOT! (Mine are and I have eyeglass prescriptions to prove it.) b) the lighting is suitable for their use. (Again, NOT a smart presumption for these tired eyes.) c) the device can handle large enough font size to compensate for the two former.

I'm surprised to learn of your reaction. As should be clear from some of the intermediate posts, ligatures, and other more advanced typographical measures, are supposed to make text easier to read, not harder. There's a lot of reseach done to suggest that we don't process every letter in every word, and rely on cues from the overall word shape, and ligatures, from what I understand, are designed in part to keep that shape consistent and "flowing".

Ligatures are in almost all professionally typeset material, and have been for centuries; most people just don't notice them. If my eyes were bad, I'd expect that I probably would just not notice them either, not that they would bother me somehow.

Similarly, if my vision were bad, I doubt I'd notice the difference between straight and curly quotation marks, but I think I'd still subliminally get part of their intended positive effect of leading the eyes.

But obviously my speculation is worthless as anything more than that. I wonder if studies have been done on their effect, and certainly, what holds good in general might not hold good for everyone... and I certainly don't dispute that they cause you trouble.

[charleski]

Originally Posted by DaleDe

I do not believe display resolution has anything to do with ligature use.

Yes, they're simply a resolution of circumstances in which the characters would otherwise collide in an unsightly manner. The ugliness is a bit more apparent on high-res displays though.

I do believe that the source eBooks should never use ligatures. Ligatures should be added by the rendering engine as one method among others to improve character tracking.

The real problem lies in the extremely limited processor power available. Since readers need to conserve power, their processors are generally very poky and barely have enough grunt to lay out the page as it is. Witness how much faster the PRS600 turns pages compared to the 505 or 300 - that's nothing to do with the display, it's simply the result of a faster processor.

While everyone gets excited about new display tech (and yes, the 225dpi Mirasol display does look quite exciting, unlike all the others that I've heard of), there are a lot of improvements that will come simply by having more horsepower under the hood. I just hope that Adobe is working on a version of ADE with a full set of rendering improvements (smart typography, hyphenation to support smart justification with tracking adjustment, etc) that will make use of the increased power of the integrated single-chip solutions that are being developed.

EBooks should be sources and not attempt to force rendering

Well, an ePub is a final delivery container rather than a source document. If you want certain features right now, your only option is to hard-code them. What matters in an ePub is what the reader sees on the screen.

[frabjous]

The real problem lies in the extremely limited processor power available. Since readers need to conserve power, their processors are generally very poky and barely have enough grunt to lay out the page as it is.

I have a hard time believing that this particular function would require much processor resources at all. Heck, the sed program, which could handle something like this, dates to 1973.

I just hope that Adobe is working on a version of ADE with a full set of rendering improvements (smart typography, hyphenation to support smart justification with tracking adjustment, etc) that will make use of the increased power of the integrated single-chip solutions that are being developed.

From your lips (or fingertips) to God's (or Adobe's) ears!

[delphidb96]

Originally Posted by frabjous

I'm surprised to learn of your reaction. As should be clear from some of the intermediate posts, ligatures, and other more advanced typographical measures, are supposed to make text easier to read, not harder. There's a lot of reseach done to suggest that we don't process every letter in every word, and rely on cues from the overall word shape, and ligatures, from what I understand, are designed in part to keep that shape consistent and "flowing".

Ligatures are in almost all professionally typeset material, and have been for centuries; most people just don't notice them. If my eyes were bad, I'd expect that I probably would just not notice them either, not that they would bother me somehow.

Similarly, if my vision were bad, I doubt I'd notice the difference between straight and curly quotation marks, but I think I'd still subliminally get part of their intended positive effect of leading the eyes.

But obviously my speculation is worthless as anything more than that. I wonder if studies have been done on their effect, and certainly, what holds good in general might not hold good for everyone... and I certainly don't dispute that they cause you trouble.

"Supposed to" is not true for me. I note that you consistently state 'if my eyes' or 'if my vision' were bad. Well, obviously it ain't so until you've read 1,000,000 pages with *my* eyes, you'll never know how hard all the ligature stuff can be on small-display devices. Don't worry, you'll get there soon enough.

Until that time, feel free to enjoy all your document formatting you so love.

Derek

[HarryT]

Originally Posted by DaleDe

I do believe that the source eBooks should never use ligatures. Ligatures should be added by the rendering engine as one method among others to improve character tracking. EBooks should be sources and not attempt to force rendering, fix tracking, etc.

"oe" and "ae" ligatures are present in pretty much every font, and are extremely common in British English, although both have been very largely replaced with a simple "e" in US English (with the interesting exception of the word "phoenix", although I note that there is a place called "Phenix City" in Alabama).

[Valloric]

Originally Posted by charleski

Witness how much faster the PRS600 turns pages compared to the 505 or 300 - that's nothing to do with the display, it's simply the result of a faster processor.

AFAIK this doesn't have much to do with a faster processor, but a better E-Ink controller - a software/firmware issue.

I could be wrong.

[DaleDe]

Originally Posted by HarryT

"oe" and "ae" ligatures are present in pretty much every font, and are extremely common in British English, although both have been very largely replaced with a simple "e" in US English (with the interesting exception of the word "phoenix", although I note that there is a place called "Phenix City" in Alabama).

Ah, yes, but I was referring to stylistic ligatures. Alphabetic ligatures are needed in the source, often just to indicate the date of the source. I would not change the spelling of a classic in this regard. But that is much different than stylistic ligatures such as the various forms of f with following letters. Those are only for presentation, not pronunciation. Even W was once an alphabetic ligature and is the youngest letter in our alphabet.

The two usages of ligatures are so different there really needs to be a different name for them.

Dale

[HarryT]

Originally Posted by DaleDe

Ah, yes, but I was referring to stylistic ligatures. Alphabetic ligatures are needed in the source, often just to indicate the date of the source.

Sorry, Dale, I'm not with you. What I mean is that, for example, British books will still almost always use the spelling "encylopædia", with a ligature, rather than use separate letters and spell the word "encyclopaedia". Is there a difference between ligatures such as "æ" and "œ" and the ones we've been discussing previously?

[DaleDe]

Originally Posted by HarryT

Sorry, Dale, I'm not with you. What I mean is that, for example, British books will still almost always use the spelling "encylopædia", with a ligature, rather than use separate letters and spell the word "encyclopaedia". Is there a difference between ligatures such as "æ" and "œ" and the ones we've been discussing previously?

Yes, those are all alphabetic ligatures. These are not what I am talking about. What I am talking about is the examples already used in this thread. You are the first to bring up alphabetic ligatures which are designed as pronunciation ligatures (function as alphabetic letters) in that they modify the phoneme itself. Check ligatures our wiki article on typography or typographic ligature in the wikipedia.

Stylistic ligatures include such things as: fi, fj fl (fl), ff (ff), ffi (ffi), and ffl (ffl). Hope this is clearer.

Dale

[HarryT]

Thanks, Dale; I didn't know until now that there was a difference between the two "types" (no pun intended) of ligature.

[delphidb96]

Originally Posted by HarryT

Thanks, Dale; I didn't know until now that there was a difference between the two "types" (no pun intended) of ligature.

There's a third kind - usually found around the necks of victims of strangulation. (See! I really DO watch too many mystery/suspense shows!)

Derek

[charleski]

Originally Posted by frabjous

I have a hard time believing that this particular function would require much processor resources at all. Heck, the sed program, which could handle something like this, dates to 1973.

Each ligature substitution is another check that needs to be made while pre-processing the stream for display. In isolation, you could probably add that in without inducing a noticeable increase in the delay. Add up all the rest, though, especially hyphenation and tracking adjustments for justification, and a 505 would crawl.

Originally Posted by Valloric

AFAIK this doesn't have much to do with a faster processor, but a better E-Ink controller - a software/firmware issue.

The Epson controller in the 600 probably makes a big difference, but I think that's largely because its paralellism frees up cycles on the main cpu (which is running twice as fast as the one in the 505).

[frabjous]

Originally Posted by charleski

Each ligature substitution is another check that needs to be made while pre-processing the stream for display. In isolation, you could probably add that in without inducing a noticeable increase in the delay. Add up all the rest, though, especially hyphenation and tracking adjustments for justification, and a 505 would crawl.

Possibly. Surely the fact that Sony-ready ePubs break their source into limited size chunks provides some help. But even if this is too much for a 505, surely we should keep pushing for something better; the hardware will surely catch up to the requirements soon if it's not there yet!

[WillAdams]

The combined forms æ and œ are diphthongs, not ligatures and should only be used when linguistically appropriate.