Compress images

[peekpoke]

Another tidbit, the to EPUB conversion has a unique option not in the AZW3 output.
"Shrink images larger than" on the EPUB output settings page.
You can absolutely use this to drastically shrink oversized images.

I can't think why this option is missing from the AZW3 output?

[kovidgoyal]

Polish books make no destructive changes you can run them on all formats repeatedly. That's part of their core goal. And there is no max image size in AZW3 because there is far less diversity in readers for that format and all o fthem support large images fine.

[peekpoke]

Originally Posted by kovidgoyal

And there is no max image size in AZW3 because there is far less diversity in readers for that format and all o fthem support large images fine.

Although Kindles can display large images, their limited resolution means it's a painful waste of limited storage capacity to include images 3200x2500 pixels (for example from "Ascendance of a Bookworm").

The Paperwhite I'm copying to is only 1072x1448. If I could limit the images on AZW3 to a maximum of 1072x1448 that would cut that image down to 1/9th the pixels with no loss in readability (no text in images).

[kovidgoyal]

limited? Last I checked kindles had GB plus storage and if you put too many books ona kindle its indexer falls over anyway.

[peekpoke]

Originally Posted by kovidgoyal

limited? Last I checked kindles had GB plus storage and if you put too many books ona kindle its indexer falls over anyway.

Kindles do get confused and often hang when given thousands of books or some crazy long books. But with less than a thousand books they usually do fine.

The issue is mostly Light Novels for example "Ascendance of a Bookworm" series which are about 34 medium length novels, around 300 pages each. A Kindle could easily handle hundreds of them except for the artwork which balloons a few megabyte book up to 30 to 40 megabytes each. Just that series alone will fill a 2GB Kindle after accounting for overhead and Amazon bloat.

Try to add a few Light Novel series, and you'd run out of space on a 4GB or even the latest 8GB models.

The artwork in those Light Novels is amazingly bloated for reading on a 6" greyscale display!

[theducks]

Calibre Polish has the option to losslessly compress images

Polish can be applied to a group (selection) of books with just a few clicks.