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,pdfa-3}] [--sidecar [FILE]] [--version] [-j
              N] [-q] [-v  [VERBOSE]]  [--title  TITLE]  [--author  AUTHOR]  [--subject  SUBJECT]
              [--keywords  KEYWORDS] [-r] [--remove-background] [-d] [-c] [-i] [--oversample DPI]
              [--remove-vectors]   [--mask-barcodes]   [--threshold]   [-f]   [-s]   [--redo-ocr]
              [--skip-big   MPixels]   [-O   {0,1,2,3}]   [--jpeg-quality  Q]  [--png-quality  Q]
              [--jbig2-lossy]    [--max-image-mpixels    MPixels]    [--tesseract-config     CFG]
              [--tesseract-pagesegmode     PSM]     [--tesseract-oem     MODE]    [--pdf-renderer
              {auto,hocr,sandwich}]   [--tesseract-timeout   SECONDS]   [--rotate-pages-threshold
              CONFIDENCE]  [--pdfa-image-compression  {auto,jpeg,lossless}]  [--user-words  FILE]
              [--user-patterns FILE] [-k] [--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,pdfa-3}
              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'. 'pdf-a3' creates a PDF/A3-b file.

       --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

       --remove-vectors
              EXPERIMENTAL.  Mask  out  any  vector  objects  in the PDF so that they will not be
              included in OCR. This can eliminate false characters.

       --mask-barcodes
              EXPERIMENTAL. Mask out any barcodes  that  appear  in  the  PDF  so  they  are  not
              considered during OCR. Barcodes can introduce false characters into OCR.

       --threshold
              EXPERIMENTAL.  Threshold  image to 1bpp before sending it to Tesseract for OCR. Can
              improve OCR quality compared to Tesseract's thresholder.

   OCR options:
              Control how OCR is applied

       -f, --force-ocr
              Rasterize any text 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

       --redo-ocr
              Attempt  to  detect and remove the hidden OCR layer from files that were previously
              OCRed with OCRmyPDF or another program. Apply OCR to text found in  raster  images.
              Existing visible text objects will not be changed. If there is no existing OCR, OCR
              will be added.

       --skip-big MPixels
              Skip OCR on pages larger than the  specified  amount  of  megapixels,  but  include
              skipped pages in final output

   Optimization options:
              Control how the PDF is optimized after OCR

       -O {0,1,2,3}, --optimize {0,1,2,3}
              Control  how  PDF  is  optimized after processing:0 - do not optimize; 1 - do safe,
              lossless optimizations  (default);  2  -  do  some  lossy  optimizations;  3  -  do
              aggressive lossy optimizations (including lossy JBIG2)

       --jpeg-quality Q
              Adjust  JPEG  quality  level for JPEG optimization. 100 is best quality and largest
              output size; 1 is lowest quality and smallest output; 0 uses the default.

       --png-quality Q
              Adjust PNG quality level to use when quantizing PNGs.  Values have same meaning  as
              with --jpeg-quality

       --jbig2-lossy
              Enable  JBIG2 lossy mode (better compression, not suitable for some use cases - see
              documentation).

   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,hocr,sandwich}
              Choose OCR PDF renderer - the  default  option  is  to  let  OCRmyPDF  choose.  See
              documentation for discussion.

       --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.

   Debugging:
              Arguments to help with troubleshooting and debugging

       -k, --keep-temporary-files
              Keep temporary files (helpful for debugging)

       --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.