[MiNT] Bit-Depth and Graphics stuff....

[Paul Wratt <paul.wratt@gmail.com>]

On Sat, Jul 17, 2010 at 7:14 PM, George Nakos <ggn@hol.gr> wrote:
> Hello Paul,
>
> Saturday, July 17, 2010, 5:18:02 AM, you wrote:
>
>> On Mon, Jul 12, 2010 at 8:57 PM, Eero Tamminen <oak@helsinkinet.fi> wrote:
>>> .. For example GIF format doesn't even support more than 8-bits
>>> and it can be used for huge background patterns.
>>> ..
>
>> actually you can generate valid GIF format images with 16 million
>> (24/32bit) colors using PHP and GD2, even though it is not an official
>> definition (of the GIF format).
>
> Wrong. Take a look at this: http://phil.ipal.org/tc.html
>
> --
> Best regards,
>  George                            mailto:ggn@hol.gr
>
Thanks for that, it basically confirmed what I already knew about GIF's.

"not an official definition" should then read "not a generally
accepted definition" and was intended to "cover my butt" in a
discussion sense

If I remember rightly, GIF format says "how may bits per color are
held in the color table". This is not the same as "how many colors are
in the color table". Therefore it is possible for a GIF to provide
24/32 bit images without providing 16 million colors in the color
table, and hence only one image block.

What ppeople should take from this is:
It is possible and "legal" to use gif images in formats greater the 256 colors

NOTE: some Atari ST software can handle GIF > 256 color. Vision is not
currently one of them

Paul