maemo.org - Talk - Screen Colours / Color Depth: 16 million or 65K?

maemo.org - Talk (https://talk.maemo.org/index.php)

- Nokia N900 (https://talk.maemo.org/forumdisplay.php?f=44)

- - Screen Colours / Color Depth: 16 million or 65K? (https://talk.maemo.org/showthread.php?t=32594)

Re: Screen Colours

Reminds me of the apple fiasco a while back.

http://www.wired.com/gadgetlab/2007/05/apple_lcd_lawsu/

Re: Screen Colours

Quote:

Originally Posted by mickeyjaw (Post 351594)

AFAIK, the beagleboard supports 24 bit colour, and uses omap3, so the n900 probably does too. OpenGL ES (3D acceleration) only works at 16bit colour depth though, and this is probably the reason why this is the colour depth used. Plus the screen will only be 18bit depth at the most anyway like all TN TFT panels. I somehow doubt they put an IPS or PVA panel in a phone...

It's worse than that, actually, when you really get down to nuts and bolts:

Quote:

TN displays suffer from limited viewing angles, especially in the vertical direction. Also, TN panels represent colors using only 6 bits per color, instead of 8, and thus are not able to display the 16.7 million color shades (24-bit truecolor) that are available from graphics cards. Instead, these panels display interpolated 24-bit color using a dithering method that combines adjacent pixels to simulate the desired shade. They can also use Frame Rate Control (FRC), which cycles pixels on and off to simulate a given shade. These color simulation methods are noticeable to many people and bothersome to some.[2] FRC tends to be most noticeable in darker tones, while dithering appears to make the individual pixels of the LCD visible. Overall, color reproduction and linearity on TN panels is poor. Shortcomings in display color gamut (often referred to as a percentage of the NTSC 1953 color gamut) are also due to backlighting technology. It is not uncommon for displays with CCFL (Cold Cathode Fluorescent Lamps)-based lighting to range from 10% to 26% of the NTSC color gamut, whereas other kind of displays, utilizing RGB LED backlights, may extend past 100% of the NTSC color gamut—a difference quite perceivable by the human eye.

http://en.wikipedia.org/wiki/TFT_LCD

Re: Screen Colours

Quote:

Originally Posted by Jack6428 (Post 350711)

Hm, so you think that only you are right or what? That you are smarter than Nokia or what? I don't understand your framebuffers, but the N900 has 16 Million colors, fact. What more do you have to know?

Quote:

Originally Posted by pycage (Post 350951)

Is it automatically a fact when stated wrong on the market spec sheet?

Here's a fact:

Code:

$ python

>>> import gtk

>>> gtk.gdk.get_default_root_window().get_depth()

16

>>>

Owned.

(Please ignore me. I serve no purpose except to make this message longer. Grr, stop looking at me!)

Re: Screen Colours

Pretty much answers that question eh :)

Re: Screen Colours

The Hildon 2.2 UI guidelines document from http://www.forum.nokia.com/info/sw.n...yle_Guide.html says:

Quote:

The basic constraints for hardware and form-factors currently supported by Hildon are:
• Screen resolution of 800x480 pixels and 16bit colour depth (65 536 colours)
• 265 dpi screen resolution

N900 color depth: 16million or 65K collors?

On every N900 brochure and advertisement I find, it shows the N900 as a device with 16 million colors (16777216, to be exact, that is 2^24, which means it should have 24 bit depth or 32 bit depth - 24 bits plus 8 from aplha channel).

However, I just compiled installed the x11-utils package from the tools repository and ran xdpyinfo, and got this:

Code:

[user@n900 user]% xdpyinfo | grep -i depth

    depth 1, bits_per_pixel 1, scanline_pad 32

    depth 4, bits_per_pixel 8, scanline_pad 32

    depth 8, bits_per_pixel 8, scanline_pad 32

    depth 15, bits_per_pixel 16, scanline_pad 32

    depth 16, bits_per_pixel 16, scanline_pad 32

    depth 24, bits_per_pixel 32, scanline_pad 32

    depth 32, bits_per_pixel 32, scanline_pad 32

  depths (7):    16, 1, 4, 8, 15, 24, 32

  depth of root window:    16 planes

    depth:    16 planes

    depth:    32 planes

[user@n900 user]%

Isn't that wrong, 16 planes? That would mean 65536 colors! Or are the brochures referring to the "maximum" capacity of the device (after all it shows 7 different possible color depths)? Can I change its depth somehow? Do games like Bounce Evolution do this?

Bounce Evolution does not change the color depth

At least not that I could check. I ran it and ran xdpyinfo from ssh:

Code:

[user@n900 user]% xdpyinfo | grep 'depth of root window'

  depth of root window:    16 planes

[user@n900 user]%

I compiled xrandr for ARM but it does not allow to change color depth, only resolution.

Re: N900 color depth: 16million or 65K collors?

On the the german n900 page it clearly states 65.536 Colors.

Interestingly, it does not say anything about colors on the Nokia USA
product page..

Re: N900 color depth: 16million or 65K collors?

on GSM arena it say 16M colours.

Re: N900 color depth: 16million or 65K collors?

Quote:

Originally Posted by Patola (Post 579840)

On every N900 brochure and advertisement I find, it shows the N900 as a device with 16 million colors

Any official references (clueless "reviewers" don't count IMO)?

FWIW http://europe.nokia.com/find-product...s#hardware-dui says "Up to 65 000 colours", which is clearly wrong but not too misleading.