pdf-question-spacer is a tool used to add whitespace to pdfs. It allows for the addition of whitespace to sections of a pdf matching a regular expression, whilst also ensuring page breaks do not cut off shifted text.
Alternatively, the user can select which regions of the pdf to add whitespace to interactively.
Using the command:
space-pdf sample.pdf 300 # Defaults to spacing lines starting with numbers
we can transform sample.pdf:
into:
More specifically, if R is a vertical region whose text matches the specified regular expression, then the specified amount of whitespace (300 in our case) is added above R.
png files will then be created in the working directory and can be converted to a pdf. For example using ImageMagick:
convert out* -page A4 my-new-pdf.pdf
Text extraction is not always perfect so the script also offers an interactive mode where the user can select which regions to add whitespace to:
space-pdf sample.pdf 300 -i
Example popup:
pip install pdf-question-spacer --user
Or using pipx:
pipx install pdf-question-spacer
ImageMagick and tesseract-ocr are also required.
usage: space-pdf [-h] [-i] [-pl PREVIEW_LENGTH] [-r REGEXES [REGEXES ...]] [-ir]
[-c COLOUR] [-s1] [-d] [--dpi DPI]
infile whitespace_length
Add whitespace to sections of pdfs and output the resulting images as pngs.
positional arguments:
infile name of pdf to add whitespace to
whitespace_length Number of lines of whitespace to add per match (in
pixels), default is 400
optional arguments:
-h, --help show this help message and exit
-i, --interactive Instead of matching lines using a regular expression,
show each region to the user and allow them to decide
whether to add whitespace or not (overrides most other
options)
-pl PREVIEW_LENGTH, --preview-length PREVIEW_LENGTH
In interactive mode, for every shown region, show the
previous <n> regions concatenated (where possible) where
n is the value passed to this argument, default is 5. Has
no effect if --interactive is not chosen
-r REGEXES [REGEXES ...], --regexes REGEXES [REGEXES ...]
Match lines with these regular expressions, in addition
to the default regex which matches lines which appear to
be the start of questions
-ir, --ignore-default-regex
Do not use the default regex which matches lines which
appear to be the start of questions. To use this option
you must also use the --regexes option
-c COLOUR, --colour COLOUR
Colour of the whitespace, default 255 (white)
-s1, --skip-first Skip first regular expression match
-d, --debug Show the text extracted from the pdf regions, along with
the corresponging region in a matplotlib figure (not
functional in interactive mode)
--dpi DPI The image quality, default is 400. This is passed
directly to pdf2image.convert_from_path(), also note
using large values will take longer and may cause
crashes!
Currently only outputs images in greyscale. Extremely large pdfs will consume large amounts of memory, so it is advised to first split the pdf up or use interactive mode (typically takes less time for large pdfs).