--bg-subsample=<1-6>

Decreases the number of pixels in the document's background layer. Because background objects are generally low-contrast and smooth, you can subsample this layer without affecting their appearance. The background of a 300 dpi document, therefore, can be subsampled to 100 dpi, which corresponds to a value of 3 (300 dpi / 100 dpi = 3). The default option of 3 decreases the size of the output file and ensures that the letters that were not placed in the foreground are still readable. The default value is set to 3.

Example

pdftodjvu --bg-subsample=5 document.pdf [document.djvu]