[Coco] [Color Computer] 1984 djvu conversion

[Jeff Teunissen]

Bob Devries wrote:
> Tim,
> I'm wondering if the difference is that I am scanning directly to PDF, not 
> first creating a JPEG file?

No, you're not actually scanning directly to PDF (that's impossible, since PDF 
is vector-based, not raster-based like scans are). Your scans are either in 
JPEG or TIFF format (or both, depending on the page), embedded inside a PDF 
container on the fly. The difference in size can be attributed to two things: 
JPEG quality settings in the compressor, and your use of 1-bit black and white 
instead of 24-bit color (which, all other things being equal, results in 24 
times more raster data)

For most kinds of document preservation, purely black and white (or even 
greyscale) scans of documents are considered unacceptable. For anything black 
and white, there's no point in converting to DjVu because it's already as 
small as it's ever going to get (and as a correlary, it's also time to locate 
better scans).