Burgwedel Friedrich
2001-Jul-02 06:25 UTC
AW: [vorbis] OT: PNG and Image compression thread
> > Actually, PNG supports bigger paletted images then that.. Of at > > least 4096 colors, probably more.That is, 4096 Colors out of possible 2^48...> If PNG supports 48 bit color, then that's actually... hm, > 2^48 = 281474976710656 colors. 4096 colors would be only 12 bits.Do you know about the difference between indexed color and 'true color'? ;P Theoretically, you might be able to have an indexed color image with 16 bits/p and 48 bit colors; you would need a palette with 2^16 entries with 48 bit each... have fun. Indexed color at 12 bits/p seems to be fair. Btw., I don't know if PNG supports indexed color with full alpha channel (not indexed alpha); does anyone know? So long Friedrich> -----Ursprüngliche Nachricht----- > Von: Jaakko Lintula [mailto:crawlie@uk2.net] > Gesendet: Montag, 2. Juli 2001 15:15 > An: vorbis@xiph.org > Betreff: Re: [vorbis] Image compression thread > > > On Monday 02 July 2001 14:50, Gregory Maxwell wrote: > > On Mon, Jul 02, 2001 at 02:36:03PM +0200, Jernej Simonèiè wrote: > > > PNG is lossless, produces smaller files than GIF, and supports > > > grayscale images from 1 to 16 bit, paletted images from 2 to 256 > > > colors/palette entries, color images up to 48 bits, transparent > > > color setting with paletted images, alpha channel (up to 16 bits) > > > with others. > > Actually, PNG supports bigger paletted images then that.. Of at > > least 4096 colors, probably more. > > If PNG supports 48 bit color, then that's actually... hm, > 2^48 = 281474976710656 colors. 4096 colors would be only 12 bits. > > --- >8 ---- > List archives: http://www.xiph.org/archives/ > Ogg project homepage: http://www.xiph.org/ogg/ > To unsubscribe from this list, send a message to > 'vorbis-request@xiph.org' > containing only the word 'unsubscribe' in the body. No > subject is needed. > Unsubscribe messages sent to the list will be ignored/filtered. >--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Burgwedel Friedrich a écrit:> That is, 4096 Colors out of possible 2^48...Except for still-SF-style "holographic archiving" I can't see use for more than 32-bit color support. Even that amount of colour is far beyond eyes capabilities... --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.