On Fri, 12 Jan 2001, Guillermo S. Romero / Familia Romero wrote:
> [EMAIL PROTECTED] (2001-01-12 at 1746.52 +0100):
> > Rebecca J. Walter wrote:
> Uumm, eeeh... GIF, JPG and many other formats are like working in 16
> bit screen. Use PNG if you want compression but keep colors nicely.
> This thing is becoming boring (sorry but day after day the lossy
> compression thing appears... is there not a FAQ somewhere or what?).
> 
> > What is the best file type to use?

GIF
only supports 256 colours. lossless compression (lzw patented). supports basic
animation. One colour may be set to transparent.
Useful for: Text, images/icons with few colours but sharp detail. Animations.
Not good for highly detailed work with many colours.

JPEG(JFIF)
24 bit colour, lossy compression, no transparency support, can blur sharp
detail.
Useful for photographs, highly detailed artwork.
Not really suited to Internet use.

PNG
Supprts 256 colour, 16 bit greyscale, 48 bit true-colour. lossless compression
(no patent), alpha channels with varying degrees of transparency, better
interlacing, most cases compression is better than gif
Useful for most things. 256 colour non dithered for web graphics, 48bit for
photographic work, 
Does not support animations (what's happend to MNG ?).

Not a FAQ but for a detailed discussion of the PNG format, one of the better
resources is the W3C, try http://www.w3.org/TR/REC-png-multi.html or their
frontdoor at http://www.w3.org/

Regards,
Dominic.



> > And is there a file type that can
> > keep work in progress? ie Five layers open for editing later?
> 
> Gimp native format is .xcf.bz2, .xcf.gz or .xcf (aka .xcf compressed
> or not). IMHO .xcf.bz2 if your machine is fast, .xcf.gz if not, .xcf
> if you want to waste HD.
> 
> GSR

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