100
CHAPTER 3 Syntax
Header
Original
body
Original
cross-reference
section
Original trailer
Body update 1
Cross-reference
section 1
Updated trailer 1
Body update n
Cross-reference
section n
Updated trailer n
FIGURE 3.3 Structure of an updated PDF file
3.4.6 Object Streams
PDF 1.5 introduces a new kind of stream, an object stream, which contains a
sequence of PDF objects. The purpose of object streams is to allow a greater
number of PDF objects to be compressed, thereby substantially reducing the size
of PDF files. The objects in the stream are referred to as compressed objects. (This