MobileRead Forums - View Single Post - Can't open California Digital Library pdfs on older Kindle

willus · 08-31-2017, 12:16 AM

I just chose a couple random books. The Alice in Wonderland PDF (from the California Digital Library) uses JPX encoding with RGB images at 8 bits per color.

On the other hand, the Western Philosophy PDF (from the Universal Library) uses JBIG2 encoding with monochrome (1 bit per pixel).

You can check encoding with k2pdfopt's "info" feature (-i command-line option).

That's probably the difference between the kindle being able to display the pages. It may be running out of memory on the JPX decode, or it may simply not know how to decode JPX.

You might want to look at this post.

08-31-2017, 12:16 AM	#2
willus Fuzzball, the purple cat Posts: 1,303 Karma: 11087488 Join Date: Jun 2011 Location: California Device: iPad	I just chose a couple random books. The Alice in Wonderland PDF (from the California Digital Library) uses JPX encoding with RGB images at 8 bits per color. On the other hand, the Western Philosophy PDF (from the Universal Library) uses JBIG2 encoding with monochrome (1 bit per pixel). You can check encoding with k2pdfopt's "info" feature (-i command-line option). That's probably the difference between the kindle being able to display the pages. It may be running out of memory on the JPX decode, or it may simply not know how to decode JPX. You might want to look at this post. Last edited by willus; 08-31-2017 at 07:49 AM. Reason: Changed "8 bits per pixel" to "8 bits per color"