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Getting Started:
    1. Windows
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  2. Linux
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  3. Mac OSX
  4. Help in other languages

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Customizing K2PDFOPT:
    1. K2pdfopt GUIs
    2. Disabling the Windows GUI
    3. The interactive menu
    4. List of command-line options
    5. Using a shortcut
  (now with video!)
  6. Using the K2PDFOPT environment variable
  7. Using the command line

Adjusting the output:
    1. Screen Size
    2. Increasing the magnification
    3. Landscape mode
    4. Output File Size
    5. Setting Margins
    6. Color Output
    7. Uneven Line Breaks/ Excess Margins

Processing Options:
    1. Showing Markings
    2. OCR
    3. Native PDF
  (now with video!)
    4. Auto-Straightening
    5. Ignoring Borders/ Headers/Footers
    6. Detecting Columns
    7. Protecting Regions
    8. Column Order
    9. Right-to-Left Page Scanning
    10. Using Ghostscript
K2pdfopt has a number of options to control when it tries to break the PDF document into multiple columns. The command-line options are -as, -col, -ch, -cgr, and -crgh. Or you can select option "co" from the interactive menu (as of v1.34) to adjust all of these values. If you don't know what to put, just go with the default, but I'll discuss what they do here.

If you are processing a photo-copied or scanned document which might not be perfectly straight, try turning on the auto-straighten / de-skew using -as. The document should be auto-straightened for the best chance of correctly detecting multiple columns.

Use the -col option to select the maximum number of columns to be detected in your document. This can realistically be 1, 2, or 4 (3 is the same as 4). It essentially sets the level of recursion that k2pdfopt will use on detected regions. That is, if you set it to 2, k2pdfopt will look for one column break in the main page. If you set it to 4, k2pdfopt will then (recursively) look for a column break within each "column" if it finds a column break on the main page. Setting to 1 will turn off multiple-column detection, i.e. k2pdfopt will not look for multiple columns. The default value for -col is 2, so you must manually set it to 4 for documents with more than 2 columns.

The figure below will be used to demonstrate three of the column detection options:


The -ch option is used to specify the minimum height for a multi-column region in inches. That is, if you use -ch 4.0, then any multi-column region within the PDF page must be at least 4 inches high, otherwise it will not be broken into multiple columns. The default value is 1.5.

The -cgr option (Column Gap Range) specifies the range over which k2pdfopt looks for a break (gap) between the columns. If it is set to 1.0, k2pdfopt will scan the entire horizontal range of the page for a column break. If it is set to 0.05, k2pdfopt will only scan the middle 5% of the page for a column break. The default is 0.33.

The -crgh option (Column Row Gap Height) specifies the minimum horizontal gap heights, in inches, that must surround each multi-column region. Setting this value higher makes it harder for k2pdfopt to find a multi-column region, because it requires the gaps to be larger. The default is 1/72 of an inch.


This page last modified
Sunday, 28-May-2017 10:09:24 PDT