Quote:
Originally Posted by Peter Ahlstrom
Still haven't heard back from my contact. But I did an experiment with KDP.
For the book we're releasing next week, I made a KDP-only version with images 1200 pixels wide. I made both a version with PNGs and a version with GIFs. (The only difference is the file format; neither has transparency, etc.) Then I uploaded them and let them process. Here are the results.
PNG version:
4.3 MB
After conversion: 4.28 MB
Delivery fee: $0.64
GIF version:
4.6 MB
After conversion: 3.83 MB
Delivery fee: $0.57
I wonder why the larger file came out smaller...
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Yesterday, I bought a book published by University of Chicago Press as azw3/azw6 from amazon and as an epub from kobo. It had 7 b&w photos with inserted black text on white background boxes and 28 line drawings.
All of the illustrations in the epub are PNG, including photos. Although the line drawing had 256 gray levels present, that was because of effective anti-aliasing because of scanning. It looks like they did make sure that the backgroung was pure full white (255,255,255).
the azw6 had the photos as wdp (JPEG-XR bitdepth=16-SIGNED, colorfmt=YONLY) and the line drawings are all GIF, 8-bit with fixed color table, which had 25 gray entries (which does not have a subset of 16 equally spaced levels). The dimensions of the original images were small enough that the output dimensions did not change, but jpeg artifacts from excessive compression were evident. The GIF images were significantly degraded compared to the PNG but I don't know whether that would be evident on an e-ink display.
In your case, it would be interesting to know the sizes oy your input GIF and PNG and the types and sizes of the KDP output images.