Jørn Are Sjulsen wrote:
> according to
> http://www.eurotechnology.com/imode/faq-handsets.html, the new
> java enabled phones all have 256 color screens, but running a small test
> program i wrote on the i-jade emulator, gives me somewhat
> different results.
> (a screenshot can be found at: http://www.uio.no/~jornas/testshot.jpg).
>
> the test program loads up 3 gif's, all with different pallettes, draws a
> portion of each to the screen, and then, using the
> Graphics.getColorOfRGB()
> method, draws one red gradient, one green gradient, and one blue gradient.
> the result is that all pictures show up just fine, while the gradients all
> seem to be using a fixed 332 rgb pallette, making them look very bad.
>
> is all this because the i-jade simulator does something weird, or can the
> phones change pallette between drawing operations? in the latter case, is
> there a limit to how many different colors that can actually be shown
> onscreen at the same time?
<snip>
A palette (or CLUT, Colour Look-Up Table) defines how the values stored
in memory for each pixel are translated into colours. Changing the
palette changes the colours on-screen (soon) since the screen doesn't
remember its state and must be refreshed from memory. Unless it's
possible to change the palette as the screen is being refreshed (a rare
feature, and one that I think a general drawing facility could not make
use of), then the palette limits how many colours you can have on-
screen.
I think that the simulator just doesn't modify images to reflect the
phones' display limitations at the moment. This is quite separate
from modifying the colours you select for drawing operations.
(There are somewhat similar problems with some video drivers for
Windows that use different algorithms to select best colours for pens
and for bitmap images, which can cause colour mismatches in web pages
- even if they use the "web-safe" colours.)
--
I do not speak for Roundpoint; any opinions I express are my own.
[ Did you check the archives? http://www.appelsiini.net/keitai-l/ ]
Received on Wed Feb 14 20:33:56 2001
