yeah i can see that. I want to know why this happening too! May be the application doesn't use hardware rendering?

But there are other devices out there listed as 16.7mil colours. Even the iPHONE 3GS spec say 16.7mils colour offially on their page.

can someone explain why isn't N900 spec say the same as the iPhone? though i can see that N900 has better clearer screen when comparing it side by side.

It's called "marketing" or in other words how to lie to you so that you buy their ****.

http://www.displaymate.com/iPhone_3GS_ShootOut.htm quote:
"The iPhone uses 18-bit color, which provides 64 possible intensity levels for each of the Red, Green and Blue sub-pixels that are used to mix and produce all of the on-screen image colors."

16M colors listed on iPhone page is a number of colors used on software level, but when it actually being drawn to a screen it is converted to 18 bit image with dithering (google for that word finally!).

A good example is a black and white newspaper photo which only uses black ink, but due to the way it is used your eyes actually see a gradation of gray color - now take a magnifying glass and look at the way it is done.
Some spots are completely black, some are completely white, but some have small dots of both, so depending on how many of those near your eyes see it as some sort of gray. Dithering on your screen is similar, yet not the same as in newspapers.

N900 screen has higher resolution and therefore higher dpi - reason it looks better.

Read some wiki on how digital images are displayed on screen, then you'll understand better the difference and can actually decide if screen depth is as important as you claim it. Don't get me wrong, it would be cool to have a 24 bit, but as long as screen is only 18, making software calculate more than that won't make much difference.

Some higher quality LCD screens do have more depth than TN does. I am a luck person with a IPS-based display and it shows true 24 bits of color.

IRC, Apple has chosen an IPS based display for its iPad, too.

You said it: you were lucky. It's not common.

The actual color format is 5+6+5 in the N900 (otherwise you don't actually get 65k colors), but excellent post either way.

Probably the desktop app pre-process the image with its own renderer using dithering algorithms to give it a smoother finish. Which actually is reasonable - those images don't change frequently enough so a bit overhead when adding them to desktop is quite acceptable - and since those are the images that users will most frequently see there is a reason to do that from a marketing/general user experience point of view.

You can see a City Bank written on a bus, that doesn't mean that you'll get any money if you enter it. iPhone has way worse screen than the N900 - color depth is the same, N900 has 2.5 more pixels thus resulting in far crisper image and especially text, and the N900 has better viewing angles (actually I'm quite surprised how good it is at that given that it uses TN-Film which by itself has abysmal viewing angles which only get worse as the dpi rises, and N900 probably has the highest DPI I've ever seen on an LCD).

Oops , I stand corrected. I forgot to consider that for the sake of color uniformity as the debate started on white-to-black gradient where additional bit to any of the colors plays no role except giving it a hardly noticeable tint. Yep, when limiting a screen to the 16-bit (or any other depth indivisible by three) you need to give an advantage to one of the colors to have 65k colors available, but when considering a grayscale we can safely say that the screen actually performs as 15-bit, which is precisely the reason why there are 32 distinguishable bars on a full white-to-black gradient.

The Neo 1973 & FreeRunner still beat it :-)

Yeah, unfortunately it is not common. You have to search for an IPS or PVA based monitor if you want 24 bits. It is even harder than that because most companies that sell those are available only in Europe, with just a few in the US. If you live somewhere else, you have to import it (a lot of trouble).

Anyway, current large TN panels seems to do 24 bit colors by doing hardware dithering (either spacial - rare or time-based dithering - more usual). That way, they "present" a 24bit interface to the OS and the user sees a good approximation of it.

It would be interesting in checking if small panels for cellphones would also be sold with controllers capable of hardware dithering. Although for it to work, the Operating System would have to send 24-bit color instructions instead of only 15 or 16-bit. Since the OpenGLES engine only seems to work at 16-bit colors mode, for the N900 there is no point, aside from curiosity.

Some tests I did here with the N900,
The result was a Next.
View a photo to the gallery of photos, it displays in 16bit
And the image display on the desktop, or videos he shows up at 32 or 24 bits.

Fassa the test, I created a video with a photo posted here.
Fassa Download and test.
The video is in 800x480 30FPS 5.5Mbps/s . MPG4

http://rs465.rapidshare.com/files/37...test_Video.zip

Turn the Video with MPlayer, It better!

Thank you all! ATT: MAYKON

Therefore, it is clear the N900's screen is capable of playing much besides just 65K colors!
The problem is the gallery of photos, which renders Images Only 16bits. The same technique used to navigate the web.

And for playing videos he renders with Over 16 Bits No doubt! Reaches 24 bit Color Video In fact it is!.

The question is? such a limitation of 16 bits Imposed by the photo gallery and the configuration of Maemo5 or photo gallery that renders only 16bit?

By remembering that put the image on the Desktop of the N900 image is displayed with 24 bits.

Ate more! Thanks!