Graphics Programs Reference
In-Depth Information
First, we'll look at the sections of the file (in the order in which they appear) and then
we'll put them together and run
pdftk
to make a valid PDF file.
File Header
The file header usually consists of two lines. The first identifies the file as a PDF and
gives its version number:
%PDF-1.0
PDF version 1.0 header
The second line is hard to type into a text editor since it contains nonprintable char-
acters. We'll have
pdftk
do this for us.
Main Objects
On to the main body of the fileāthe objects. The first is the
page list
, which is a dic-
tionary linking to the page objects in the document.
1 0 obj
Object 1
<< /Type /Pages
It's a page list
/Count 1
There is one page
/Kids [2 0 R]
List of object numbers of pages. Just object 2 here.
>>
endobj
End of object 1
Next up is the
page
. Again, it's a dictionary. It contains the paper size, an indirect
reference back to the page list, and to the graphical content and
resources
.
2 0 obj
<< /Type /Page
It's a page
/MediaBox [0 0 612 792]
Paper size is US Letter Portrait (612 points by 792 points)
/Resources 3 0 R
Reference to resources at object 3
/Parent 1 0 R
Reference back up to parent page list
/Contents [4 0 R]
Graphical content is in object 4
>>
endobj
Now, the
resources
. Here, there is just one entry, the
font dictionary
, which in our
example contains a single font, which we're going to use to write some text on the page.
3 0 obj
<< /Font
The font dictionary
<< /F0
Just one font, called /F0
<< /Type /Font
These three lines reference the built-in font Times Italic
/BaseFont /Times-Italic
/Subtype /Type1 >>
>>
>>
endobj