PDF Format Reference - Adobe Portable Document Format

CHAPTER 4

196

Graphics

Although the painting behavior described above is often attributed to individual

operators making up an object, it is always the object as a whole that is painted.

objects. Some operations are permitted only in certain types of graphics objects

or in the intervals between graphics objects (called the

page description level

the figure). Every content stream begins at the page description level, where

changes can be made to the graphics state, such as colors and text attributes, as

discussed in the following sections.

In the figure, arrows indicate the operators that mark the beginning or end of

each type of graphics object. Some operators are identified individually, others by

general category. Table 4.1 summarizes these categories for all PDF operators.

TABLE 4.1 Operator categories