|  | 
   
 |   |  |   
  
    | UNPAPER(1) | unpaper | UNPAPER(1) |  
unpaper [options] (input patterns output
    patterns | input files output files) 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
    misaligned 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. Input and output files need to be designed either by using
    patterns or an ordered list of input and output files; if patterns are used,
    such as %04d, then they are substituted for the input and output
    sheet number before opening the file for input or output. If you're not using patterns, then the program expects one or two
    input files depending on what is passed as --input-pages and one or
    two output files depending on what is passed as --output-pages, in
    order. Missing output file names are fatal and will stop processing;
    missing initial input file names are fatal, and so is any missing input file
    if a range of sheets is defined through --sheet or
    --end-sheet. unpaper accepts files in PNM format, which means they might
    be in .pbm, .pgm, .ppm or .pnm format, which is
    what is produced by Linux command line scanning tools such as
    scanimage and scanadf. 
 
 
  -end sheet ; --end-sheet
    sheetNumber of last sheet to process in multi-sheet mode. -1 indicates
      processing until no more input file with the corresponding page number is
      available (default: -1) 
 
  -# sheet-range ; --sheet sheet-rangeOptionally specifies which sheets to process in the range between
      start-sheet and end-sheet. 
 
 
 
 
 
  --post-mirror { v | h |
    v,h }Mirror the image, after any other processing except possible
      post-rotation. Either v (for vertical mirroring), h (for
      horizontal mirroring) or v,h (for both) can be specified. 
 
  --pre-shift h,
    vShift the image before further processing. Values for h (horizontal shift)
      and v (vertical shift) can either be positive or negative. 
 
  --post-shift h,
    vShift the image after other processing. Values for h (horizontal shift)
      and v (vertical shift) can either be positive or negative. 
 
  --pre-wipe left, top,
    right, bottomManually wipe out an area before further processing. Any pixel in a wiped
      area will be set to white. Multiple areas to be wiped may be specified by
      multiple occurrences of this options. 
 
  --post-wipe left, top,
    right, bottomManually wipe out an area after processing. Any pixel in a wiped area will
      be set to white. Multiple areas to be wiped may be specified by multiple
      occurrences of this options. 
 
 
 
  --pre-mask x1, y1, x2,
    y2Specify masks to apply before any other processing. Any pixel outside a
      mask will be set to white, unless another mask includes this pixel.
    Only pixels inside a mask will remain. Multiple masks may be
        specified. No deskewing will be applied to the masks specified by
        --pre-mask. 
 
  -s { width, height | size-name }
    ; --size { width, height | size-name }Change the sheet size before other processing is applied. Content on the
      sheet gets zoomed to fit to the appropriate size, but the aspect ratio is
      preserved. Instead, if the sheet's aspect ratio changes, the zoomed
      content gets centered on the sheet.
    Possible values for size-name are: a5, a4,
        a3, letter, legal. All size names can also be
        applied in rotated landscape orientation, use a4-landscape,
        letter-landscape etc. 
 
 
 
 
 
  --post-zoom
    factorChange the sheet size according to the given factor after processing is
      done. 
 
  -bn { v | h | v, h } ;
    --blackfilter-scan-direction { v | h | v, h }Directions in which to search for solidly black areas. Either v
      (for vertical searching), h (for horizontal searching) or
      v,h (for both) can be specified. The blackfilter works by moving a
      virtual bar across each page. The darkness inside the virtual bar is
      determined and if it exceeds blackfilter-scan-threshold black
      pixels in the area are filled. During filling the blackness of each pixel
      is determined by black-threshold. The bar is then moved by
      blackfilter-scan-step in the scanning direction. Once a page border
      is encountered the bar is moved down (horizontal scan) or right (vertical
      scan) by its blackfilter-scan-size. 
 
 
 
 
 
 
  -bi intensity ;
    --blackfilter-intensity intensityIntensity with which to delete black areas. This deletes pixels around the
      virtual scan bar. Larger values will leave less noise-pixels around former
      black areas, but may delete page content. (default: 20) 
 
 
 
 
  -li ratio ;
    --blurfilter-intensity ratioRelative intensity with which to delete tiny clusters of pixels. Any
      blurred area which contains at most the ratio of dark pixels will be
      cleared. (default: 0.01) 
 
 
 
 
  -p x, y; --mask-scan-point x,
    yManually set starting point for mask-detection. Multiple
      --mask-scan-point options may be specified to detect multiple
      masks. 
 
  -m x1, y1, x2, y2; --mask x1, y1,
    x2, y2Manually add a mask, in addition to masks automatically detected around
      the --mask-scan-point coordinates (unless --no-mask-scan is
      specified).
    Any pixel outside a mask will be set to white, unless another
        mask covers this pixel. 
 
  -mn { v \| h \| v,h };
    --mask-scan-direction { v \| h \| v,h }Directions in which to search for mask borders, starting from
      --mask-scan-point coordinates. Either v (for vertical mirroring),
      h (for horizontal mirroring) or v,h (for both) can be
      specified. (default: h, as v may cut text- paragraphs on
      single-page sheets) 
 
 
 
 
 
  -mm w, h; --mask-scan-minimum
    w, hMinimum allowed size of an auto-detected mask. Masks detected below this
      size will be ignored and set to the size specified by mask-scan-maximum.
      (default: 100,100) 
 
  -mM w, h; --mask-scan-maximum
    w, hMaximum allowed size of an auto-detected mask. Masks detected above this
      size will be shrunk to the maximum value, each direction individually.
      (default: sheet size, or page size derived from --layout
    option) 
 
  -mc color; --mask-color
    colorColor value with which to wipe out pixels not covered by any mask. Maybe
      useful for testing in order to visualize the effect of masking. (Note that
      an RGB-value is expected: R*65536 + G*256 + B.) 
 
  -dn { left \| top \| right \|
    bottom },...; --deskew-scan-direction { left \| top \| right \| bottom
    },...Edges from which to scan for rotation. Each edge of a mask can be used to
      detect the mask's rotation. If multiple edges are specified, the average
      value will be used, unless the statistical deviation exceeds
      --deskew-scan-deviation. Use left for scanning from the left
      edge, top for scanning from the top edge, right for scanning
      from the right edge, bottom for scanning from the bottom. Multiple
      directions can be separated by commas. (default: left,right) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  -b threshold; --black-threshold
    thresholdBrightness ratio below which a pixel is considered black (non-gray). This
      is used by the gray-filter and the blackfilter. This value is also used
      when converting a grayscale image to black-and-white mode (default:
      0.33) 
 
  -ip { 1 \| 2 }; --input-pages {
    1 \| 2 }If 2 is specified, read two input images instead of one and
      internally combine them to a doubled-layout sheet before further
      processing. Before internally combining, --pre-rotation is
      optionally applied individually to both input images as the very first
      processing steps. 
 
  -op { 1 \| 2 }; --output-pages
    { 1 \| 2 }If 2 is specified, write two output images instead of one, as a
      result of splitting a doubled-layout sheet after processing. After
      splitting the sheet, --post-rotation is optionally applied
      individually to both output images as the very last processing step. 
 
  -S { width, height \| size-name
    }; --sheet-size { width, height \| size-name }Force a fix sheet size. Usually, the sheet size is determined by the input
      image size (if input-pages=1), or by the double size of the first
      page in a two-page input set (if input-pages=2). If the input image
      is smaller than the size specified here, it will appear centered and
      surrounded with a white border on the sheet. If the input image is bigger,
      it will be centered and the edges will be cropped. This option may also be
      helpful to get regular sized output images if the input image sizes
      differ. Standard size-names like a4-landscape, letter, etc.
      may be used (see --size). (default: as in input file) 
 
  --sheet-background {
    black \| white }Sets a color with which the sheet is filled before any image is loaded and
      placed onto it. This can be useful when the sheet size and the image size
      differ. 
 
 
 
 
 
  --no-mask-scan
    sheet-rangeDisables mask-detection. Masks explicitly set by --mask will still
      have effect. Individual sheet indices can be specified. 
 
  --no-mask-center
    sheet-rangeDisables auto-centering of each mask. Auto-centering is performed by
      default if the --layout option has been set. Individual sheet
      indices can be specified. 
 
 
  --no-wipe
    sheet-rangeDisables explicit wipe-areas. This means the effect of parameter
      --wipe can be disabled individually per sheet. 
 
  --no-border
    sheet-rangeDisables explicitly set borders. This means the effect of parameter
      --border can be disabled individually per sheet. 
 
 
  --no-border-align
    sheet-rangeDisables aligning of the area detected by border-scanning (see
      --border-align). Individual sheet indices can be specified. 
 
  -n sheet-range; --no-processing
    sheet-rangeDo not perform any processing on a sheet except pre/post rotating and
      mirroring, and file-depth conversions on saving. This option has the same
      effect as setting all --no-xxx options together. Individual sheet
      indices can be specified. 
 
 
  --no-multi-pagesDisable multi-page processing even if the input filename contains a
      % (usually indicating the start of a placeholder for the page
      counter). 
 
  --dpi dpiDots per inch used for conversion of measured size values, like e.g.
      21cm,27.9cm. Mind that this parameter should occur before
      specifying any size value with measurement suffix. (default:
    300) 
 
  -t { pbm \| pgm \| ppm }; --type
    { pbm \| pgm> \| ppm }Output file type (and bit depth). If not specified, the one with the same,
      or closest, pixel format as the original input files will be used. 
  pbmPortable Bit Map, monochrome raw image.pgmPortable Grayscale Map, 8-bit per pixel grayscale raw image.ppmPortable Pixel Map, 24-bit per pixel RGB raw image. 
 
  -T ; --test-onlyDo not write any output. May be useful in combination with
      --verbose to get information about the input. 
 
  -si nr; --start-input
    nrSet the first page number to substitute for '%d' in input filenames. Every
      time the input file sequence is repeated, this number gets increased by 1.
      (default: (startsheet-1)*inputpages+1) 
 
  -so nr; --start-output
    nrSet the first page number to substitute for '%d' in output filenames.
      Every time the output file sequence is repeated, this number gets
      increased by 1. (default: (startsheet-1)*outputpages+1) 
 
  --insert-blank nr
    [,nr...]Use blank input instead of an input file from the input file sequence at
      the specified index-positions. The input file sequence will be interrupted
      temporarily and will continue with the next input file afterwards. This
      can be useful to insert blank content into a sequence of input
    images. 
 
  --replace-blank nr
    [,nr...]Like --insert-blank, but the input images at the specified index
      positions get replaced with blank content and thus will be ignored. 
 
  --overwriteAllow overwriting existing files. Otherwise the program terminates with an
      error if an output file to be written already exists. 
 
 
 
  -vvEven more verbose output, show parameter settings before processing. 
 
 2020, The unpaper Authors 
  Visit the GSP FreeBSD Man Page Interface. Output converted with ManDoc.
 |