The layer option decodes only the layer of the DjVu® image that you specify. Supported layer types are the following: foreground, background, mask, and all (default). For example:
djvutojpeg
--layer=background landscape.djvu landscape.jpeg
In this example the output file, landscape.jpeg, contains only the background layer of the original DjVu image. If you specify a layer that is not present in the image, the image is skipped during the decoding process.
Supporting commands:
djvudecode
For more information, see Segmenter Options.