libdjvulibre-dev 3.5.28-2build2 (riscv64 binary) in ubuntu lunar

 DjVu image format static library and development files.
 .
 DjVu is a set of compression technologies, a file format, and a
 software platform for the delivery over the Web of digital documents,
 scanned documents, and high resolution images.
 .
 DjVu documents download and display extremely quickly, and look
 exactly the same on all platforms. DjVu can be seen as a superior
 alternative to PDF and Postscript for digital documents, to TIFF (and
 PDF) for scanned documents, to JPEG for photographs and pictures, and
 to GIF for large palettized images. DjVu is the only Web format that
 is practical for distributing high-resolution scanned documents in
 color.