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Old 07-13-2016, 08:56 PM   #10
geekmaster
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Posts: 6,433
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Join Date: Nov 2011
Location: Multiverse 6627A
Device: K1 to PW3
Quote:
Originally Posted by DDRBoxman View Post
I've attached a png that was generated and run through pngcrush.

It still has the same stretching issue from the initial post, I also changed to passing the -g and -f flags to eips.

Guess I'll start looking into direct framebuffer access.
The "stretching issue" is likely due to the fact (as I said) that pixels are doubled in 8-bit mode (each byte contains the same pixel value in top and bottom 4-bits). You may be trying to pack two pixels into each byte.

The simplest thing to do is pure black and white where each byte contains 0 or 255, and that also avoids a full flash update (how gmplay does it). If you can display images but they are "squashed" try converting to 8-bit color (but 16-color color pallete 0x00 0x11 0x22 0x33 ... 0xff, with duplicate colors to extend it evenly to 256 colors). For an example examine the color histogram of screensaver images (where you will see 16 unique colors in a palette of 256 colors).

To see how these pixels are packed, examine code in my "newtrix" demo (though its eink updates do not work on newer kindles).

Last edited by geekmaster; 07-13-2016 at 09:42 PM.
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