Figure 1. Relationships between PDFMiner objects
PDF documents are more like graphics, rather than text documents. It presents no logical structure such as sentences or paragraphs (for most cases). -PDFMiner tries to reconstruct the original structure by performing +PDFMiner attempts to reconstruct some of these structures by performing basic layout analysis.
- - +Here is a typical way to do it:
from pdfminer.layout import LAParams
from pdfminer.converter import PDFPageAggregator
@@ -86,40 +87,96 @@ device = PDFPageAggregator(rsrcmgr, laparams=laparams)
interpreter = PDFPageInterpreter(rsrcmgr, device)
for page in doc.get_pages():
interpreter.process_page(page)
- # receive the top-level layout object.
- ltpage = device.get_result()
+ # receive the LTPage object for the page.
+ layout = device.get_result()
-
-
-
LTPage- -
LTTextBox- -
LTTextLine- -
LTChar- -
LTText- -
LTFigure- -
LTImage- -
LTRect- -
LTPolygon- -
LTLine-
LTPage" object for each page
+in the PDF document. The object contains child objects within the page,
+forming a tree-like structure. Figure 2 shows the relationship between
+these objects.
+
+
+Figure 2. Layout objects and its tree structure +
-
+
-
LTPage+ - Represents an entire page. May contain child objects like
+
LTTextBox,LTFigure,LTImage,LTRect, +LTPolygonandLTLine. + + -
LTTextBox+ - Represents a group of text chunks that can be contained in a rectangular area.
+Note that this box is created by geometric analysis and does not necessarily
+represents a logical boundary of the text.
+It contains a list of
LTTextLineobjects. + + -
LTTextLine+ - Contains a list of
LTCharobjects that represent +a single text line. The characters are aligned either horizontaly +or vertically, depending on the text's writing mode. + + -
LTChar+LTText+ - These objects represent an actual letter in the text as a Unicode string.
+Note that, while a
LTCharobject has actual boundaries, +LTTextobjects does not, as these are "virtual" characters, +inserted by a layout analyzer according to the relationship between two characters +(e.g. a space). + + -
LTFigure+ - Represents an area used by PDF Form objects. PDF Forms can be used to
+present figures or pictures by embedding yet another PDF document within a page.
+Note that
LTFigureobjects can appear recursively. + + -
LTImage+ - Represents an image object. Embedded images can be +in JPEG or other formats, but currently PDFMiner does not +pay much attention to graphical objects. + +
-
LTLine+ - Represents a single straight line shown in a page. +Could be used for separating texts or figures. + +
-
LTRect+ - Represents a rectangle shown in a page. +Could be used for framing another pictures or figures. + +
-
LTPolygon+ - Represents a polygon in a page. +
TOC Extraction
++PDFMiner provides functions to access the document's table of contents +("Outlines").
+from pdfminer.pdfparser import PDFParser, PDFDocument
+
fp = open('mypdf.pdf', 'rb')
parser = PDFParser(fp)
doc = PDFDocument()
parser.set_document(doc)
doc.set_parser(parser)
doc.initialize(password)
+
# Get the outlines of the document.
outlines = doc.get_outlines()
for (level,title,dest,a,se) in outlines:
print (level, title)
+In some PDF documents, destinations are referred to as page numbers. +In other PDF documents, destinations are referred to as page numbers plus +the location within the page. Since PDF does not provide a way to +point to graphical objects in a page, normally these in-page destinations +are specified by physical coordinates.
Yusuke Shinyama