Working with pages
This section details with how to view and edit the contents of a page.
pikepdf is not an ideal tool for producing new PDFs from scratch – and there are many good tools for that, as mentioned elsewhere. pikepdf is better at inspecting, editing and transforming existing PDFs.
Pages in PDFs are wrappers around dictionary objects.
In [1]: from pikepdf import Pdf, Page
In [2]: example = Pdf.open('../tests/resources/congress.pdf')
In [3]: page1 = example.pages[0]
In [4]: page1
Out[4]:
<pikepdf.Page({
"/Contents": pikepdf.Stream(owner=<...>, data=b'q\n200.0000 0 0 304.0'..., {
"/Length": 50
}),
"/MediaBox": [ 0, 0, 200, 304 ],
"/Parent": <reference to /Pages>,
"/Resources": {
"/XObject": {
"/Im0": pikepdf.Stream(owner=<...>, data=<...>, {
"/BitsPerComponent": 8,
"/ColorSpace": "/DeviceRGB",
"/Filter": [ "/DCTDecode" ],
"/Height": 1520,
"/Length": 192956,
"/Subtype": "/Image",
"/Type": "/XObject",
"/Width": 1000
})
}
},
"/Type": "/Page"
})>
The page’s /Contents
key contains instructions for drawing the page content.
This is a content stream, which is a stream object
that follows special rules.
Also attached to this page is a /Resources
dictionary, which contains a
single XObject image. The image is compressed with the /DCTDecode
filter,
meaning it is encoded with the DCT, so it is
a JPEG. pikepdf has special APIs for working with images.
The /MediaBox
describes the bounding box of the page in PDF pt units
(1/72” or 0.35 mm).
You can access the page dictionary data structure directly, but it’s fairly
complicated. There are a number of rules, optional values and implied values.
To do so, you would access the page1.obj
property, which returns the
underlying dictionary object that holds the page data.
Note
In pikepdf 2.x, the raw dictionary object was returned, and it was
necessary to manually wrap it with the support model:
page = Page(pdf.pages[0])
. This is no longer necessary, but also
harmless.
Page boxes
In [5]: page1.trimbox
Out[5]: pikepdf.Array([ 0, 0, 200, 304 ])
Page
will resolve implicit information. For example, page.trimbox
will return an appropriate trim box for this page, which in this case is
equal to the media box. This happens even if the page does not define
a trim box.