05-25-2012, 08:52 AM | #16 | |
Carpe diem, c'est la vie.
Posts: 6,433
Karma: 10773668
Join Date: Nov 2011
Location: Multiverse 6627A
Device: K1 to PW3
|
Quote:
|
|
05-25-2012, 08:54 AM | #17 | |
Evangelist
Posts: 404
Karma: 2200000
Join Date: May 2012
Device: kt
|
Quote:
First of all adding function keys and special characters might be tricky. It would also probably require changing system files, while using separate virtual keyboard does not. |
|
Advert | |
|
05-25-2012, 08:57 AM | #18 | |
Carpe diem, c'est la vie.
Posts: 6,433
Karma: 10773668
Join Date: Nov 2011
Location: Multiverse 6627A
Device: K1 to PW3
|
Quote:
How can inverting the dithering give more "b/w pixels"? EDIT: The newtrix demo also shows how to blit full grayscale, so you can have 256 shades of gray. Even on the K4 and K5 that use 8-bit pixels, the bottom 4 bits must be a copy of the top 4 bits (according to comments in the device driver source code). You can get unpredictable results (depending on eink controller hardware) if the bottom 4 bits are not the same as the top 4 bits in a pixel. So to get more than 16 shades of gray, dithering is required (as shown in newtrix, which supports 256 shades of gray as can be seen in the shaded circular background image behind the "hoses"). Last edited by geekmaster; 05-25-2012 at 09:04 AM. |
|
05-25-2012, 09:24 AM | #19 |
Connoisseur
Posts: 58
Karma: 63518
Join Date: Apr 2012
Device: KT
|
Maybe i misunderstood something but i thought i have read somewhere, that the kindle itself does gray-scale with dithering. For my stupid understanding of dithering that means: they use 4 pixels(example) for one to display some shades of grey. So if i can predict how my 16 gray-scale colors will be dithered to the screen i have access to more pixels, so i can make my font/image/whatever even more clear(in black and white pixels)
I bet this thought is just bullshit - right? (Nevertheless i found some results to "Invert ordered dithering" on Google, so maybe only my assumption, that the e-ink display uses dithering, is wrong) Last edited by MaPePeR; 05-25-2012 at 09:29 AM. |
05-25-2012, 09:32 AM | #20 |
Carpe diem, c'est la vie.
Posts: 6,433
Karma: 10773668
Join Date: Nov 2011
Location: Multiverse 6627A
Device: K1 to PW3
|
The kindle PROGRAMS (such as eips) do the dithering. If you put a 256-grayscale PNG image on the kindle, then display it with "eips -g file.png", then save the image in the framebuffer with "dd if=/dev/fb0 of=file.raw", then load the raw image into a paint program and do a histogram analysis on it, you will see spikes for only 16 evenly-spaced shades of gray. The raw image in the framebuffer was dithered from 256 colors to 16 colors by eips. Similar dithering is done for screensaver images and for ads. I do software dithering for 256-color support in the newtrix demo program -- you can look at my published C source code to see how I did it.
"Invert/inverse dithering/halftoning" is the process of converting a dithered image back to grayscale. It averages pixels in "continuous tone" areas to get 8-bit color values, but original dithered pixels are retained near discontinuities (high-gradient edges in the image). This is similar to "super-resolution" upscaling, where pixel-smoothing is done in the direction of least-gradient. When we OUTPUT to the eink display we do dithering because the hardware only supports 16 shades of gray for STATIC images (like anti-aliased text), or only 2 shades of gray (pure black and white) for ANIMATION (such as the videos in the "geekmaster kindle video player" thread). EDIT: For text fonts used on older laser printers, individual pixels were placed BY HAND around the edges of characters, to dither the edges in a way that was pleasing to the eye. This dithering was designed into the character bitmaps by "font artists", rather than being done by software or hardware. Because the kindles behave more like ink on paper than like light-emitting displays, these old time-tested ways of doing this give much better results when speed is important (such as on animated displays). Last edited by geekmaster; 05-25-2012 at 09:53 AM. |
Advert | |
|
05-25-2012, 09:55 AM | #21 |
Connoisseur
Posts: 58
Karma: 63518
Join Date: Apr 2012
Device: KT
|
|
05-25-2012, 10:00 AM | #22 | |
Carpe diem, c'est la vie.
Posts: 6,433
Karma: 10773668
Join Date: Nov 2011
Location: Multiverse 6627A
Device: K1 to PW3
|
Quote:
In the newtrix demo, I also dither 256 shades of gray down to 16, as required by the eink hardware. On the K3 and earlier, each framebuffer byte holds two 4-bit pixels. On the K4 and newer, each framebuffer byte holds two COPIES of a 4-bit pixel. You can see how I handle this in the newtrix demo. Last edited by geekmaster; 05-25-2012 at 10:04 AM. |
|
05-25-2012, 11:50 AM | #23 |
Enthusiast
Posts: 27
Karma: 5790
Join Date: Jan 2009
Location: moscow, russia
Device: Kindle Touch, Sony PRS-505
|
Thanks for realizing my wishes!
works like a charm. is it possible to change fonts, Midnight Commander looks ugly enough? now we can use many console tools, like console instant messengers, and so on. edit&compile with tcc... Nice! Last edited by wl.; 05-25-2012 at 12:08 PM. |
05-25-2012, 01:53 PM | #24 |
Evangelist
Posts: 404
Karma: 2200000
Join Date: May 2012
Device: kt
|
|
05-25-2012, 02:06 PM | #25 |
Enthusiast
Posts: 27
Karma: 5790
Join Date: Jan 2009
Location: moscow, russia
Device: Kindle Touch, Sony PRS-505
|
look at these, which uses GTK+ (already inside kindle), wxWidgets (easy to compile and install). Maybe . NET Mono (easy to compile, hard to install, and waste space).
qutIM - should be the best choose, but Qt4 itself has no access for Kindle Touch (i mean, there is no "./configure && make" sources, which will work on KT without glitches) |
05-26-2012, 06:25 PM | #27 |
Enthusiast
Posts: 27
Karma: 5790
Join Date: Jan 2009
Location: moscow, russia
Device: Kindle Touch, Sony PRS-505
|
|
05-26-2012, 11:24 PM | #28 |
but forgot what it's like
Posts: 741
Karma: 2345678
Join Date: Dec 2011
Location: north (by northwest)
Device: Kindle Touch
|
KT on-screen keyboard isn't a Java application. It's a native compiled application. It sends X events to currently active window.
So potentially it could be used with XTerm (and any other X application). Keyboard layouts are simple JSON files (gzipped in 5.1.0). X keysyms could be used in a keyboard layout (i.e. cursor keys, control keys etc). A little more information could be found in another thread. Keyboard could be shown with: Code:
lipc-set-prop -s com.lab126.keyboard open com.example.xterm:abc:1 Code:
lipc-set-prop -s com.lab126.keyboard close com.example.xterm Unfortunately, KT keyboard doesn't working with XTerm from this thread. Keyboard send X events of key presses to XTerm window, XTerm receives them (I see it in debug level logs of keyboard application and xev output for XTerm window). But XTerm doesn't display sent characters. I didn't dig any further. UPD Full list of keyboards sub-layouts (as for 5.1.0): abc, Abc, 123, web, pad Flags are:
Last edited by eureka; 06-01-2012 at 08:34 PM. Reason: full list of names of flags and keyboard sub-layouts |
05-28-2012, 01:01 AM | #29 |
Guru
Posts: 608
Karma: 1588610
Join Date: Jan 2012
Device: Kindle Scribe
|
This is amazing!
|
05-28-2012, 01:33 AM | #30 |
Guru
Posts: 608
Karma: 1588610
Join Date: Jan 2012
Device: Kindle Scribe
|
Weird bug detected! If my command starts with "ipkg" then it freezes before I finish the command.
|
Tags |
launcher add-ons |
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[Progress] Jailbreaking Kindle 4.0 (Touch/No Keyboard) | yifanlu | Kindle Developer's Corner | 434 | 04-22-2016 10:29 AM |
Battery life in kindle keyboard an kindle non touch. | ersott | Amazon Kindle | 24 | 10-30-2013 04:33 AM |
[Kindle Touch] Touch-screen keyboard demo | JoppyFurr | Kindle Developer's Corner | 6 | 05-19-2012 11:04 AM |
Kindle Touch add new keyboard | Novas | Kindle Developer's Corner | 2 | 01-12-2012 08:29 AM |
Matchbox Keyboard Update | Grimulkan | iRex | 17 | 05-13-2009 04:24 PM |