MobileRead Forums - View Single Post - I found way to vastly improve displaying of text!

scotty1024 · 10-02-2006, 06:09 PM

Sorry, now I understand what you are pointing out.

Your document uses a media box larger than the screen of the iLiad. This then forces the iLiad to scale your text PDF's as well.

The text should look crisp even then but here your document falls into a typographic trap.

In a perfect world one would render from the outline information included in the font file to make wonderful looking glyphs for each character at whatever size is requested.

In the real world the rendering engine cheats to keep performance high. Built in fonts will have so called "pre-rendered glyphs" e.g. already rendered characters for the even type sizes: 12, 10, 8. To get the odd sizes the engine will scale the existing even glyphs.

But to make matters worse...

When you scale a letter sized document down to an iLiad screen a 12pt font will be roughly 7pt, not precisely 7pt. The rendering engine will do what it can but the resulting glyph is not going to look as sharp as it could.

In Postscript one could turn off this pre-rendering behavior, the laser printer would take more memory and more time, but your marked pieces of paper would be crisper.

I don't know if xpdf supports doing that, and even if it does, iRex would have it turned on to keep speed up and battery use lower.

What do I do?

I use a font I bought: Tiresias (http://www.myfonts.com/fonts/bitstream/tiresias/) and have it embedded into my PDF documents (automatic in most cases.)

I set the font size above 14pt (to avoid pre-rendered glyphs), use the correct media box (iLiad actual viewable area sized) and I get text so crisp and sharp I can shave with it.

10-02-2006, 06:09 PM	#6
scotty1024 Banned Posts: 1,300 Karma: 1479 Join Date: Jul 2006 Location: Peoples Republic of Washington Device: Reader / iPhone / Librie / Kindle	Sorry, now I understand what you are pointing out. Your document uses a media box larger than the screen of the iLiad. This then forces the iLiad to scale your text PDF's as well. The text should look crisp even then but here your document falls into a typographic trap. In a perfect world one would render from the outline information included in the font file to make wonderful looking glyphs for each character at whatever size is requested. In the real world the rendering engine cheats to keep performance high. Built in fonts will have so called "pre-rendered glyphs" e.g. already rendered characters for the even type sizes: 12, 10, 8. To get the odd sizes the engine will scale the existing even glyphs. But to make matters worse... When you scale a letter sized document down to an iLiad screen a 12pt font will be roughly 7pt, not precisely 7pt. The rendering engine will do what it can but the resulting glyph is not going to look as sharp as it could. In Postscript one could turn off this pre-rendering behavior, the laser printer would take more memory and more time, but your marked pieces of paper would be crisper. I don't know if xpdf supports doing that, and even if it does, iRex would have it turned on to keep speed up and battery use lower. What do I do? I use a font I bought: Tiresias (http://www.myfonts.com/fonts/bitstream/tiresias/) and have it embedded into my PDF documents (automatic in most cases.) I set the font size above 14pt (to avoid pre-rendered glyphs), use the correct media box (iLiad actual viewable area sized) and I get text so crisp and sharp I can shave with it.