Re: Q: Default bpp resolution 32 in Linux?

[Lee Elliott <LeeE@spatial.freeserve.co.uk>]

Marcelo Ramos wrote:
> 
> On Tue, Nov 07, 2000 at 12:52:37PM +0100, Jonathan Gift wrote:
> > Hi,
> >
> > While I realise you can have many different color depths, I remember reading
> > (but am not sure) that 32bpp is the Linux default... assuing the card
> > supports it.
> >
> > I just want to check if that's so and what difference that makes with 24
> > bit, sice the number of colors is the same?
> >
> 
> The number of colors is not the same.
> 
> With 24bpp you have the color of each pixel represented by a binary number with
> 24 bits (bit = 0 or 1), then you have 2^24 = 16.777.216 colors.
> 
> With 32bpp you have the color of each pixel represented by a binary number with
> 32 bits, then you have 2^32 = 4.294.967.296 colors.
> 
> If you want a given resolution HxV with Nbpp you video card must have at least
> (H * V * N) / (1024^2) Kbytes of memory.
> 
> Marcelo.
> 
Hello,

I don't think that using 32bpp increases the number of colours that can
be used - 32bpp is generally used as 24bpp (8bpp each for RGB) + 8bpp
alpha channel.  16bpp is split R=5bpp, G=6bpp & B=5bpp.  I've seen 36bpp
scanners and they do work with more colours - 12bpp each for RGB.

LeeE