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From: naughton@wind.eng.sun.com (Patrick Naughton)
Newsgroups: comp.windows.news
Subject: Re: what the hell happened to writecanvas in NeWS 2.0!!!
Message-ID: <134314@sun.Eng.Sun.COM>
Date: 11 Apr 90 19:56:28 GMT
References: <29898@ppgbms.UUCP>
Sender: news@sun.Eng.Sun.COM
Reply-To: naughton@wind.eng.sun.com (Patrick Naughton)
Lines: 29

In article <29898@ppgbms.UUCP>, pablo@ppgbms (Pablo Gonzalez) writes:
> Does anybody know if the raster file generated by the writecanvas primitive 
> running under NeWS 2.0 is any different from NeWS 1.1.? If so, what is the
> difference.
> 
> The reason I ask is that we have noticed a difference in the file sizes
> between rester files generated under NeWS 1.1 and the same image generated
> under NeWS 2.0. It appears that NeWS 2.0 is compressing it's data.
> 
>         Thanks,
>         Pablo

Both NeWS 1.1 and NeWS 2.0 (OpenWindows) write compressed images,
actually run-length byte encoded images.  The size difference you are
seeing is due to the inclusion of the colormap in the NeWS 1.1 image
even though it is one bit deep.  NeWS 2.0 leaves the colormap out of
1 bit deep images thus all mono images 2.0 writes will be 768 bytes
smaller than the 1.1 equivalents.

> P.S. Has any body successfully converted their NeWS 1.1 applications to 
>      NeWS 2.0? 

yes...  Many of the demos shipped with OpenWindows were converted directly
from their NeWS 1.1 predecessors.

    ______________________________________________________________________
    Patrick J. Naughton				    ARPA: naughton@sun.com
    Window Systems Group			    UUCP: ...!sun!naughton
    Sun Microsystems, Inc.			    AT&T: (415) 336 - 1080