Provided by: ocrmypdf_6.1.2-1ubuntu1.1_all 
NAME
ocrmypdf - add an OCR text layer to PDF files
DESCRIPTION
usage: ocrmypdf [-h] [-l LANGUAGE] [--image-dpi DPI]
[--output-type {pdfa,pdf,pdfa-1,pdfa-2}] [--sidecar [FILE]] [--version] [-j N] [-q]
[-v [VERBOSE]] [--title TITLE] [--author AUTHOR] [--subject SUBJECT] [--keywords
KEYWORDS] [-r] [--remove-background] [-d] [-c] [-i] [--oversample DPI] [-f] [-s]
[--skip-big MPixels] [--max-image-mpixels MPixels] [--tesseract-config CFG]
[--tesseract-pagesegmode PSM] [--tesseract-oem MODE] [--pdf-renderer
{auto,tesseract,hocr,sandwich}] [--tesseract-timeout SECONDS]
[--rotate-pages-threshold CONFIDENCE] [--pdfa-image-compression
{auto,jpeg,lossless}] [--user-words FILE] [--user-patterns FILE] [--skip-repair]
[-k] [-g] [--flowchart FLOWCHART] input_pdf_or_image output_pdf
Generates a searchable PDF or PDF/A from a regular PDF.
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.
positional arguments:
input_pdf_or_image
PDF file containing the images to be OCRed (or '-' to read from standard input)
output_pdf
Output searchable PDF file (or '-' to write to standard output). Existing files
will be ovewritten. If same as input file, the input file will be updated only if
processing is successful.
optional arguments:
-h, --help
show this help message and exit
-l LANGUAGE, --language LANGUAGE
Language(s) of the file to be OCRed (see tesseract --list-langs for all language
packs installed in your system). Use -l eng+deu for multiple languages.
--image-dpi DPI
For input image instead of PDF, use this DPI instead of file's.
--output-type {pdfa,pdf,pdfa-1,pdfa-2}
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. 'pdf-a1' creates a
PDF/A1-b file. 'pdf-a2' is equivalent to 'pdfa'.
--sidecar [FILE]
Generate sidecar text files that contain the same text recognized by Tesseract.
This may be useful for building a OCR text database. If FILE is omitted, the
sidecar file be named {output_file}.txt If FILE is set to '-', the sidecar is
written to stdout (a convenient way to preview OCR quality). The output file and
sidecar may not both use stdout at the same time.
--version
Print program version and exit
Job control options:
-j N, --jobs N
Use up to N CPU cores simultaneously (default: use all).
-q, --quiet
Suppress INFO messages
-v [VERBOSE], --verbose [VERBOSE]
Print more verbose messages for each additional verbose level
Metadata options:
Set output PDF/A metadata (default: copy input document's metadata)
--title TITLE
Set document title (place multiple words in quotes)
--author AUTHOR
Set document author
--subject SUBJECT
Set document subject description
--keywords KEYWORDS
Set document keywords
Image preprocessing options:
Options to improve the quality of the final PDF and OCR
-r, --rotate-pages
Automatically rotate pages based on detected text orientation
--remove-background
Attempt to remove background from gray or color pages, setting it to white
-d, --deskew
Deskew each page before performing OCR
-c, --clean
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
-i, --clean-final
Clean page as above, and incorporate the cleaned image in the final PDF. Might
remove desired content.
--oversample DPI
Oversample images to at least the specified DPI, to improve OCR results slightly
OCR options:
Control how OCR is applied
-f, --force-ocr
Rasterize any fonts or vector objects on each page, apply OCR, and save the
rastered output (this rewrites the PDF)
-s, --skip-text
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
--skip-big MPixels
Skip OCR on pages larger than the specified amount of megapixels, but include
skipped pages in final output
Advanced:
Advanced options to control Tesseract's OCR behavior
--max-image-mpixels MPixels
Set maximum number of pixels to unpack before treating an image as a decompression
bomb
--tesseract-config CFG
Additional Tesseract configuration files -- see documentation
--tesseract-pagesegmode PSM
Set Tesseract page segmentation mode (see tesseract --help)
--tesseract-oem MODE
Set Tesseract 4.0 OCR engine mode: 0 - original Tesseract only; 1 - neural nets
LSTM only; 2 - Tesseract + LSTM; 3 - default.
--pdf-renderer {auto,tesseract,hocr,sandwich}
Choose OCR PDF renderer - the default option is to let OCRmyPDF choose.auto - let
OCRmyPDF choose; sandwich - default renderer for Tesseract 3.05.01 and newer; hocr
- default renderer for older versions of Tesseract; tesseract - gives better
results for non-Latin languages and Tesseract older than 3.05.01 but has problems
with some versions of Ghostscript; deprecated
--tesseract-timeout SECONDS
Give up on OCR after the timeout, but copy the preprocessed page into the final
output
--rotate-pages-threshold CONFIDENCE
Only rotate pages when confidence is above this value (arbitrary units reported by
tesseract)
--pdfa-image-compression {auto,jpeg,lossless}
Specify how to compress images in the output PDF/A. 'auto' lets OCRmyPDF decide.
'jpeg' changes all grayscale and color images to JPEG compression. 'lossless' uses
PNG-style lossless compression for all images. Monochrome images are always
compressed using a lossless codec. Compression settings are applied to all pages,
including those for which OCR was skipped. Not supported for --output-type=pdf ;
that setting preserves the original compression of all images.
--user-words FILE
Specify the location of the Tesseract user words file. This is a list of words
Tesseract should consider while performing OCR in addition to its standard language
dictionaries. This can improve OCR quality especially for specialized and technical
documents.
--user-patterns FILE
Specify the location of the Tesseract user patterns file.
--skip-repair
Normally OCRmyPDF automatically repairs PDFs using qpdf before processing. If you
have already run qpdf or a similar program that repairs PDF errors, you can tell
OCRmyPDF to skip repair with this option. This may be helpful in batch processing
where all files are repaired prior to OCR occurs, since repair is single threaded
and time consuming for large files.
Debugging:
Arguments to help with troubleshooting and debugging
-k, --keep-temporary-files
Keep temporary files (helpful for debugging)
-g, --debug-rendering
Render each page twice with debug information on second page
--flowchart FLOWCHART
Generate the pipeline execution flowchart
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.
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.
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 --skip-text to ignore pages with
text, or --force-ocr to rasterize all objects on the page and produce an image-only PDF as
output.
ocrmypdf --skip-text file_with_some_text_pages.pdf output.pdf
ocrmypdf --force-ocr word_document.pdf output.pdf
If you are concerned about long-term archiving of PDFs, use the default option
--output-type 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 --output-type pdf.
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 img2pdf, or
other image to PDF software.
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 --pagesize A4 page*.png | ocrmypdf - myfile.pdf
HTML documentation is located at:
/usr/share/doc/ocrmypdf/html/index.html
after installing the ocrmypdf-doc package.