unpaper is a post-processing tool for scanned sheets of paper,
especially for book pages that have been scanned from previously
created photocopies. The main purpose is to make scanned book pages
better readable on screen after conversion to PDF. Additionally,
unpaper might be useful to enhance the quality of scanned pages before
performing optical character recognition (OCR).
unpaper tries to clean scanned images by removing dark edges that
appeared through scanning or copying on areas outside the actual page
content (e.g. dark areas between the left-hand-side and the
right-hand-side of a double-sided book-page scan). The program also
tries to detect disaligned centering and rotation of pages and will
automatically straighten each page by rotating it to the correct
angle. This process is called "deskewing".
Note that the automatic processing will sometimes fail. It is always
a good idea to manually control the results of unpaper and adjust the
parameter settings according to the requirements of the input. Each
processing step can also be disabled individually for each sheet.
Input and output files can be in either .pbm, .pgm or
.ppm format, thus generally in .pnm format, as also used by the Linux
scanning tools scanimage and scanadf. Conversion to PDF can e.g. be
achieved with the Linux tools pgm2tiff, tiffcp and tiff2pdf.
This is a fork of the original unpaper software by D.E. "Flameeyes"
Petteno'.
BUILD OPTIONS:
SPHINX => set to 'true' to build the manpage for unpaper, which now
requires "Sphinx" (available in SBo), which is a large python package
with many dependencies. Thus, it is disabled by default.
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