--tobitonal=[<1-255>]

The tobitonal option converts a color or grayscale image into a bitonal image with a specified threshold value between 1 and 255. Experiment to determine the best value for your image; most images require a value between 100–130 for an acceptable conversion.

As an alternative to experimentation, you can assign the tobitonal option a value of true (the default when you specify this option without a value). For a true value, a histogram is used to determine an appropriate thresholding level. For example:

documenttodjvu --tobitonal=true Q1.tif Q2.tif Q3.tif Q4.tif 2001annualreport.djvu

In this example, the tobitonal option converts the color input images (Q1.tif, Q2.tif, etc.) into a bitonal bundled DjVu^® document (2001annualreport.djvu).

Use this option to ensure that all your bitonal output files have small file sizes. If you inadvertently scan a bitonal document as color, this option eliminates the additional image data that is typically incorporated into a color image during the encoding process.

Supporting commands:

documenttodjvu, djvudecode