How To Outline and Bitmapped

Typefaces are what you get to admire after your work is finished, but fonts
are the tools you have to wrestle with in the meantime to get the job done.
Computer operating systems and applications have made it much easier to
work with fonts, but the process is still quite technical. Working with fonts
forces you to learn more about your computer than you probably want, but
everything you need to know is in this chapter.

The Two Basic Kinds of Fonts:
Outline and Bitmapped

Digital devices—computer monitor screens, desktop printers, imagesetters—
create images out of dots. The simplest way to create type for one of
these devices is to draw a picture of every character as an array of dots and
store these drawings in a font. Then all a device has to do to image the type is
to copy those dots into place on the screen or page. When this technology was
first figured out, each one of those dots was represented by one bit of computer
data—a simple yes/no choice of whether to image a dot or not. Images created
from these predrawn, prearranged arrays of dots were called bitmaps, and fonts
using this trick were called bitmapped fonts.

Bitmaps are a clever and simple approach, but the more dots a bitmap
contains, the more computer data it requires. As the resolution of the device
increases or the size of the character images increases, the number of dots
grows geometrically: Doubling the size of a character quadruples the number
of dots. You also need a separate set of bitmaps—a separate font—for every
size of type you want to create. And the bitmaps designed for one resolution
will appear much smaller when imaged on a device with a higher resolution,
where the dots are much smaller (see Figure 4.1). To image a single typeface
at the same range of sizes on a computer screen, a desktop printer, and an
imagesetter, then, would require hundreds of bitmapped fonts.

The solution is to store the descriptions of the characters as a set of outline
drawings. Outline fonts, which do just this, store character images as outlines
described mathematically as a series of curves and straight-line segments.
(These line segments are sometimes called vectors; and the fonts based on them,
vector fonts.) These outlines can be mathematically scaled to any size without
distorting the shapes or proportions of the characters. The scaled outlines are
then colored in with dots of the size created by the device that the type is being
imaged on: around 100 dots per inch (dpi) for a computer screen, approximately
600 dpi for a desktop printer, and well over 1,000 dpi for imagesetters.

While it was once common for operating systems to use bitmapped fonts
for screen display, they now generate screen type from the same outline fonts
used for high-resolution printing. Some fonts may contain sets of hand-tuned
bitmapped screen fonts for use at small sizes because they’re more legible than
those generated by your computer. But these embedded screen fonts are not
apparent to the user, and you don’t have to concern yourself with them.

Post By Computer Zoom Design