.\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.47.4.
.TH OCRMYPDF "1" "November 2016" "ocrmypdf 4.3.2" "User Commands"
.SH NAME
ocrmypdf \- add an OCR text layer to PDF files
.SH DESCRIPTION
usage: ocrmypdf [\-h] [\-\-verbose [VERBOSE]] [\-\-version] [\-n] [\-\-flowchart FILE]
.IP
[\-l LANGUAGE] [\-j N] [\-\-image\-dpi DPI]
[\-\-output\-type {pdfa,pdf}] [\-\-title TITLE] [\-\-author AUTHOR]
[\-\-subject SUBJECT] [\-\-keywords KEYWORDS] [\-r]
[\-\-remove\-background] [\-d] [\-c] [\-i] [\-\-oversample DPI] [\-f]
[\-s] [\-\-skip\-big MPixels] [\-\-tesseract\-config CFG]
[\-\-tesseract\-pagesegmode PSM]
[\-\-pdf\-renderer {auto,tesseract,hocr}]
[\-\-tesseract\-timeout SECONDS]
[\-\-rotate\-pages\-threshold CONFIDENCE] [\-k] [\-g]
input_file output_file
.PP
Generates a searchable PDF or PDF/A from a regular PDF.
.PP
OCRmyPDF rasterizes each page of the input PDF, optionally corrects page
rotation and performs image processing, runs the Tesseract OCR engine on the
image, and then creates a PDF from the OCR information.
.SS "positional arguments:"
.TP
input_file
PDF file containing the images to be OCRed (or '\-' to
read from standard input)
.TP
output_file
output searchable PDF file (or '\-' to write to
standard output)
.SS "optional arguments:"
.TP
\fB\-h\fR, \fB\-\-help\fR
show this help message and exit
.TP
\fB\-l\fR LANGUAGE, \fB\-\-language\fR LANGUAGE
Language(s) of the file to be OCRed (see tesseract
\fB\-\-list\-langs\fR for all language packs installed in your
system). To specify multiple languages, join them with
\&'+' or issue this argument once for each language.
.TP
\fB\-j\fR N, \fB\-\-jobs\fR N
Use up to N CPU cores simultaneously (default: use
all)
.TP
\fB\-\-image\-dpi\fR DPI
for input image instead of PDF, use this DPI instead
of file's
.TP
\fB\-\-output\-type\fR {pdfa,pdf}
Choose output type. 'pdfa' creates a PDF/A\-2b
compliant file for long term archiving (default,
recommended) but may not suitable for users who want
their file altered as little as possible. 'pdfa' also
has problems with full Unicode text. 'pdf' attempts to
preserve file contents as much as possible.
.SS "Common options:"
.TP
\fB\-\-verbose\fR [VERBOSE], \fB\-v\fR [VERBOSE]
Print more verbose messages for each additional
verbose level.
.TP
\fB\-\-version\fR
show program's version number and exit
.SS "pipeline arguments:"
.TP
\fB\-n\fR, \fB\-\-just_print\fR
Don't actually run any commands; just print the
pipeline.
.TP
\fB\-\-flowchart\fR FILE
Don't run any commands; just print pipeline as a
flowchart.
.SS "Metadata options:"
.IP
Set output PDF/A metadata (default: use input document's metadata)
.TP
\fB\-\-title\fR TITLE
set document title (place multiple words in quotes)
.TP
\fB\-\-author\fR AUTHOR
set document author
.TP
\fB\-\-subject\fR SUBJECT
set document subject description
.TP
\fB\-\-keywords\fR KEYWORDS
set document keywords
.SS "Image preprocessing options:"
.IP
Options to improve the quality of the final PDF and OCR
.TP
\fB\-r\fR, \fB\-\-rotate\-pages\fR
automatically rotate pages based on detected text
orientation
.TP
\fB\-\-remove\-background\fR
attempt to remove background from gray or color pages,
setting it to white
.TP
\fB\-d\fR, \fB\-\-deskew\fR
deskew each page before performing OCR
.TP
\fB\-c\fR, \fB\-\-clean\fR
clean pages from scanning artifacts before performing
OCR, and send the cleaned page to OCR, but do not
include the cleaned page in the output
.TP
\fB\-i\fR, \fB\-\-clean\-final\fR
clean page as above, and incorporate the cleaned image
in the final PDF
.TP
\fB\-\-oversample\fR DPI
oversample images to at least the specified DPI, to
improve OCR results slightly
.SS "OCR options:"
.IP
Control how OCR is applied
.TP
\fB\-f\fR, \fB\-\-force\-ocr\fR
rasterize any fonts or vector objects on each page,
apply OCR, and save the rastered output (this rewrites
the PDF)
.TP
\fB\-s\fR, \fB\-\-skip\-text\fR
skip OCR on any pages that already contain text, but
include the page in final output; useful for PDFs that
contain a mix of images, text pages, and/or previously
OCRed pages
.TP
\fB\-\-skip\-big\fR MPixels
skip OCR on pages larger than the specified amount of
megapixels, but include skipped pages in final output
.SS "Advanced:"
.IP
Advanced options for power users
.TP
\fB\-\-tesseract\-config\fR CFG
additional Tesseract configuration files
.TP
\fB\-\-tesseract\-pagesegmode\fR PSM
set Tesseract page segmentation mode (see tesseract
\fB\-\-help\fR)
.TP
\fB\-\-pdf\-renderer\fR {auto,tesseract,hocr}
choose OCR PDF renderer \- the default option is to let
OCRmyPDF choose. The 'tesseract' PDF renderer is more
accurate and does a better job and document structure
such as recognizing columns. It also does a better job
on non\-Latin languages. However, it does not work as
well when older versions of Tesseract or Ghostscript
are installed, and some combinations of arguments to
do not work with \fB\-\-pdf\-renderer\fR tesseract.
.TP
\fB\-\-tesseract\-timeout\fR SECONDS
give up on OCR after the timeout, but copy the
preprocessed page into the final output
.TP
\fB\-\-rotate\-pages\-threshold\fR CONFIDENCE
only rotate pages when confidence is above this value
(arbitrary units reported by tesseract)
.SS "Debugging:"
.IP
Arguments to help with troubleshooting and debugging
.TP
\fB\-k\fR, \fB\-\-keep\-temporary\-files\fR
keep temporary files (helpful for debugging)
.TP
\fB\-g\fR, \fB\-\-debug\-rendering\fR
render each page twice with debug information on
second page
.PP
OCRmyPDF attempts to keep the output file at about the same size.  If a file
contains losslessly compressed images, and output file will be losslessly
compressed as well.
.PP
PDF is a page description file that attempts to preserve a layout exactly.
A PDF can contain vector objects (such as text or lines) and raster objects
(images).  A page might have multiple images.  OCRmyPDF is prepared to deal
with the wide variety of PDFs that exist in the wild.
.PP
When a PDF page contains text, OCRmyPDF assumes that the page has already
been OCRed or is a "born digital" page that should not be OCRed.  The default
behavior is to exit in this case without producing a file.  You can use the
option \fB\-\-skip\-text\fR to ignore pages with text, or \fB\-\-force\-ocr\fR to rasterize
all objects on the page and produce an image\-only PDF as output.
.IP
ocrmypdf \fB\-\-skip\-text\fR file_with_some_text_pages.pdf output.pdf
.IP
ocrmypdf \fB\-\-force\-ocr\fR word_document.pdf output.pdf
.PP
If you are concerned about long\-term archiving of PDFs, use the default option
\fB\-\-output\-type\fR pdfa which converts the PDF to a standardized PDF/A\-2b.  This
converts images to sRGB colorspace, removes some features from the PDF such
as Javascript or forms. If you want to minimize the number of changes made to
your PDF, use \fB\-\-output\-type\fR pdf.
.PP
If OCRmyPDF is given an image file as input, it will attempt to convert the
image to a PDF before processing.  For more control over the conversion of
images to PDF, use the Python package img2pdf or other image to PDF software.
.PP
For example, this command uses img2pdf to convert all .png files beginning
with the 'page' prefix to a PDF, fitting each image on A4\-sized paper, and
sending the result to OCRmyPDF through a pipe.  img2pdf is a dependency of
ocrmypdf so it is already installed.
.IP
img2pdf \fB\-\-pagesize\fR A4 page*.png | ocrmypdf \- myfile.pdf
.SS "HTML documentation is located at:"
.IP
\fI\,/usr/share/doc/ocrmypdf/html/index.html\/\fP
.PP
after installing the ocrmypdf\-doc package.