Troubleshooting Kindle font rendering inferior than Sony?

[budalb]

I have Kindle DXG and installed 2.5 font hack. When I try to use Sony PRS-600's font file, the display quality is horrible, while PRS-600 displays font quite well. Then I decide to try different fonts with the same text paragraph and embed fonts in PDF. The PDF display is much better than mobi display with the same font and the same text.

Does anybody have the same issue? Did I miss anything in setting up the font file? They are all ttf.


Thanks
budalb

[NiLuJe]

Could you attach/link to the fonts in question? (And a proper screenshot of what they look like on a Sony, since I don't have one ;p)

[budalb]

Updated with pictures. Sony PRS-600 picture is not so good maybe due to its display quality. It is clear that "t" in Kindle is not well rendered. Sony's rendering is closer to paper's. The Kindles fonts are not as smooth as Sony's.

From left to right: Kindle DXG, Sony PRS-600, paper, Kindle DXG with PDF embed font

BTW The font is Century School BT from Microsoft Office.

[NiLuJe]

Yeah, I'd have to take a look at the specific font file you used, there might be some trickery with TT instructions or hinting involved somewhere... .

In general, thin full Serif fonts tend to look like crap on e-Ink displays, but the font on your Sony screenshot seems to be noticeably heavier, so, if it's the exact same file, Sony's rendering engine is probably doing something differently. Hence why I'd like to take a look at the font file, see if I can pinpoint what might explain the Kindle's rendering.

[budalb]

I can't upload font file due to copyright. It is from Microsoft Office. If I make PDF with embed fonts and read on Kindle, the display quality is as good as paper (see updated the picture). So the font rendering of mobi in Kindle definitely has issues, but not PDF.

[NiLuJe]

Yeah, I'd guess the TT hinting instructions (if any) are a bit weird, which isn't surprising on a font as old as this one, with multiple formats/hinting instructions for each format piling up long after the font has been designed, and the settings used by the mobi reader engine don't play nice with that (in fact, the mobi reader doesn't use bytecode TT hinting instructions, at least in fw 2.x, AFAICT).

It should theoretically be possible to tweak the font to play nice with the Kindle's settings, but since the font is copyrighted, and I don't own Microsoft Office, err...

And PDF embeds usually prefers the Type1/2 (Postscript) (all of them more or less being Adobe's babies) variants of a font over TrueType (more or less *not* Adobe's baby [Apple's, in fact]), which may explain why you're seeing a different rendering with a PDF, because they're using a whole different set of hinting instructions, and outline tracing method (quadratic bezier curves vs. cubic bezier curves).

[budalb]

Since Sony is using ADE's epub rendering, so it DOES confirm that Kindle's font rendering is inferior compared to Sony's. Once K3 gets font hack, it is really nice to see whether K3 improves font rendering.

Unfortunately my version of MS Office does not contain the Century School BT so I cannot see how many files are associated with it. But a lot of fonts have many files. Arial for example has quite a few, including Arial Regular (arial.ttf), Arial Narrow (arialn.ttf), Arial Bold (arialbd.ttf). Is it possible that Century School BT has a narrow (light) version and you accidentally copied that file into the Kindle font folder as Serif_Regular.ttf?

[NiLuJe]

@budalb: I wouldn't say that. I would say that ADE is probably tailored to PS outlines, being Adobe's baby, while the Kindle's renderer (the specific FreeType settings used, at least on fw 2.x) is favoring TT outlines while disregarding any bytecode TT hinting, which works pretty well for most of the fonts, except at very small sizes. Although, on an e-Ink screen, these settings tend to be very unforgiving for thin full Serif fonts, yeah. (I don't care much for full Serif fonts, whatever the rendering engine, so I may be a little bit biased here ^^)

If you feed crappy TTF conversion of Type1/2 fonts to the Kindle, they'll look like crap. Even more so if FT's autohinter handles them badly.

But I'm pretty sure that, in this specific case, it's only a matter of finding a proper TTF conversion of that font, or doing it ourselves. Unfortunately, it's copyrighted, so we can't really do that .

Or we could also try feeding the Kindle a PS font disguised as a .ttf, since FreeType handles PS fonts perfectly. (never tried that, though).

Anyway, we can't judge any of the renderer based on one flimsy test like that, when we're not sure exactly what type of font was used in each case .

Granted, I'm heavily biased towards FreeType, because, IMHO, appart maybe from Adobe's SPR renderer used in Acrobat, it's miles away in terms of readabilty from both Apple & Microsoft renderers .

@jswinden: It's actually Century Schoolbook BT, and, AFAICT, there's no light variant. (Or if there is, it's bundled Opentype-style in the Roman font).

[harryE123]

why is the text on the amazon one so garbage?

[NiLuJe]

Because you didn't read/understand anything that I said? ^^

Font rendering is a very complex thing.

Long story short: the renderer/settings used by the Kindle (mobi reader) are tweaked towards making the default fonts look good. That said, it's also fairly good with the vast majority of correctly built TT fonts. And in that specific example, I'm fairly sure that this specific font *can* be rendered correctly, provided it's properly converted/tweaked to TTF.

[harryE123]

I did try to read what you said, I just found it too technical and lost my interest along the way. Thanks for the reply though. So why would someone hack the kindle to add more fonts if the kindle has good rendering and enough available fonts? I don't understand.

btw, on that picture the kindle fonts are garbage, regardless of if I read your prior comments or not.

Originally Posted by harryE123

I did try to read what you said, I just found it too technical and lost my interest along the way. Thanks for the reply though. So why would someone hack the kindle to add more fonts if the kindle has good rendering and enough available fonts? I don't understand.

btw, on that picture the kindle fonts are garbage, regardless of if I read your prior comments or not.

None of the major companies make ebook readers with the ability to add fonts. You are stuck with the one or few fonts they place on the reader. Some of us can see and read other fonts better, and so we like to add them. For example, I added Arial Rounded MT Bold to my Kindle DX Graphite (see attachment). It renders very well on the Kindle. The font the guy added to his does not because it is a terribly made font.

The first screen capture is the font I added, the second is the default font included with the reader. Some really like the default font, whereas I personally like the font I added. It is merely a matter of personal preference and has nothing to do with whether the reader is a Kindle, a Sony, a Nook, or some other brand. I also modified my Sony Reader to have a more pleasing font. I've yet to be happy with the default font(s) on any reader, so that is why I hack the fonts. Unlike printed books where you are stuck with whatever font(s) the book was printed in, ebooks were designed to allow the reader to choose the fonts they desire, much like web browsers allow you to change the fonts. Unfortunately, most ebook reader manufacturers don't won't to give us a choice so they circumvent the ebook formatting capabilities.

...

[harryE123]

oh i see, thanks for explaining, appreciate it. So how many fonts does the kindle provide, are we talking about 5-6 or 20-30 as it should be?

Originally Posted by harryE123

oh i see, thanks for explaining, appreciate it. So how many fonts does the kindle provide, are we talking about 5-6 or 20-30 as it should be?

We wished it was that many. The Kindle DX gives you only one choice for most book text, plus a couple or so more for headings. But you cannot change them without a hack. The same goes for the Sony Readers that are currently out, but I do not know about the new ones about to hit the market. The new Kindle WiFi and Kindle WiFi + 3G actually allows you to choose between three fonts for basic text. If we had a choice of 20+ we would probably be happy with at least one, but sadly it is mostly no choice or up to three at most. Hence the reason we hack the fonts.