Around 17 o'clock on Aug 21, Markus Kuhn wrote:
> Is hinting really worth the effort? If you separate "hinting" into the two pieces supported by TrueType (instructions and deltas), then I would agree that the instruction portion is irrelevant. Good TrueType output is almost always generated by delta hints which are size-specific. > - For DTP applications, it is important that the on-screen > representation approximates as closely as possible the printed result > in a device-independent way, and hinting severely interferes > with that goal as it changes glyph spacings and sizes. When reading or editing a document on screen, the glyphs should be hinted to make the letters sharp and easy to read. How applications adjust to the differences between screen and printer metrics is a separate issue. The Windows problem is exacerbated by the lack of printer metrics through the GDI interface. Using FreeType, applications would have access to the underlying glyph sizes and be able to adjust the display to make it more closely approximate what would appear should the document be presented at higher resolution. > a) edit the resulting bi-level bitmap (switch some pixels > on or off to improve the looks) Obviously uninteresting as it eliminates anti-aliasing and sub-pixel rendering. > b) manually snap control points to a nearby pixel boundary Unless you're careful, this is covered by the TrueType delta-hint patent which covers any relative motion of control points(!) for the purpose of adjusting glyph shapes on the display. TrueType uses the combination of size-independent instructions and delta-hints to reduce the total size of the font; delta hints are only needed for "important" glyphs where the instructions don't get the right results. > - I understand that the area of scale-independent hinting instructions > in font file formats has some patent problems. (?) One of the techniques used in the instructed hinting is patented. This involves the separation of the basis of measurement from the basis for adjustment. One obvious application of this is in hinting diagonal stems -- the hint "measures" the width of the diagonal element while "adjusting" the control points along a horizontal line to keep the corners of the glyph at the same elevation. > - In spite of the sophisticated hinting mechanisms available in > TrueType fonts, it seems that places like Microsoft Typography > do not make very significant use of it and embeds handedited > bitmaps instead. Very few western TrueType fonts include bitmaps; they rely instead on delta hints. Embedded bitmaps are relegated to Han fonts and are provided at only a very few sizes. Keith Packard XFree86 Core Team HP Cambridge Research Lab _______________________________________________ Fonts mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/fonts
