# Bad ghosting on K3 screensaver



## PHJF (Feb 11, 2011)

The default screensavers looked fine, but since jailbreaking and putting on my own screensaver there is really bad ghosting from whatever was on the screen as I put the Kindle to sleep.

I've taken this image

http://www.curragh-labs.org/blog/wp-content/uploads/2010/01/gunslinger-born.jpg

cropped to 600x800
set to RGB 8bit
cranked the contrast/lowered brightness

but I can still plainly see/read ghost text anywhere that isn't PURELY black.

This wasn't a problem at all with the default screensavers and they had a ton of white/light gray in them. What gives?


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## Morf (Nov 18, 2010)

I've got a theory (I have a lot of those  ) that the Kindle has several different screen refreshes...

1) When you navigate the menus or use up and down to go through books, it doesn't refresh the screen at all, just switches the parts of the display that need switching. Because e-ink is not perfect at this time, this leaves ghosting (the "line" from a selected book is one obvious example I'm sure we've all seen.

2) When you change the page in a book, it does a page refresh (you see current page, then negative image of new page, then new page I think). This forces the e-ink screen to refresh enough that there is little or no residual ghosting left.

3) When you switch to/ out of the screensaver, (and maybe if you have a graphics page in a book, not sure) it does a double refresh - you seem to see screen saver, then negative image of screen saver, then blank screen, then negative new page, then new page. Presumably this is to give the e-ink an extra "kick" to shake all those blobs of dye around.

I've not got the screensaver hack on my Kindle, but it's possible that the hack doesn't do the screensavers in quite the same way, and doesn't do the double refresh.

Alternatively, it's possible that even the double refresh is not enough to fully clear the screen, and Amazon have customised the standard images in clever ways to avoid this problem.

This might even explain why Emily Dickinson looks so scary!  



Anyway, I guess the key is, e-ink is not yet perfect - there are still compromises between speed of page change and quality (ie ghosting) which they are handling as best they can.

I think the simple answer is, if you see the ghosting while using your Kindle normally then you've possibly got a fault. If you only see it on the screensavers, then you're going to have to either change the image, go back to the defaults, or just put up with it.

Even if my theory is correct (they often aren't  ) there's not a lot you can do about it I don't think.

Hope this helps!


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## Ann in Arlington (Oct 27, 2008)

Morf has an interesting theory. 

If you see ghosting while the device is in use, <alt><g> will do a refresh and clear it. But I don't think you can when it's on a sleep picture because, by design, when it's sleeping the keys are locked.


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## PHJF (Feb 11, 2011)

OK I figured something out.

PURE WHITES have almost no ghosting at ALL. In that Gunslinger image, most of the "white" at the top of the image is actually light gray. After cleaning up the image and making most of the background 255/255/255 white, there is almost indiscernible ghosting. The rest of the image is so dark that ghosting is difficult to see.

I gave the same treatment to this image (it used to be entirely gray and filled with ghosting) and now it looks great. So to minimize ghosting I would say to try and keep screensavers to more of a silhouette-type job.


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