View Single Post
Old 06-30-2017, 12:45 AM   #5
roger64
Wizard
roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.roger64 ought to be getting tired of karma fortunes by now.
 
Posts: 2,625
Karma: 3120635
Join Date: Jan 2009
Device: Kindle PW3 (wifi)
@Dalede

I did apologize on the first post of this thread from "hopping from thread to thread" and I did quote willus. I apologize once more. For completeness sake, here are your two quotes:

Quote:
Originally Posted by DaleDe View Post
There are two kinds of PDF's. One is an image (with or without some search text) and the second is pure text which is likely the kind you are testing with. Typically DJVU shines with an set of images that look like text. DJVU looks at the images and breaks them up into reusable graphics items that look for all intents and purposes like a set of fonts and then just references these as needed. This is typically better compression than an image would be, also the latest PDF is now using a better (JP2000) compression than it did formerly.
Dale
Quote:
Originally Posted by DaleDe View Post
You might want to start with our DJVU wiki page.
Dale
I did look at this page and many others not only from MR wiki, believe me. More advisable for beginners is probably this one that I also read carefully.

My initial idea was to hope that since one online service (convertio) proposed to convert directly Epub files to djvu, it was maybe possible to use this format to benefit from its generally acknowledged size-saving qualities.

The tests I did and reported above made me realize that I was wrong. It appears that these qualities appear (or apply) only when converting one image or a set of images. Indeed I did obtain this expected size-saving advantage only with a PDF color image and with the PDF Gallica scan (I guess it would have been the same for other image formats, except maybe for JPEG 2000 but this last one carries its own drawbacks). It's a significant achievement for djvu format in this PDF everywhere world but it did not fulfill my initial purpose.

Last edited by roger64; 06-30-2017 at 01:28 AM. Reason: for djvu format
roger64 is offline   Reply With Quote