Date: Sun, 02 Jul 2000 14:32:27 -0400 From: "Louis A. Mamakos" <louie@TransSys.COM> To: Chuck Robey <chuckr@picnic.mat.net> Cc: Garance A Drosihn <drosih@rpi.edu>, Will Andrews <andrews@technologist.com>, papowell@astart.com, arch@FreeBSD.ORG Subject: Re: was: Bringing LPRng into FreeBSD? Message-ID: <200007021832.OAA19781@whizzo.transsys.com> In-Reply-To: Your message of "Fri, 30 Jun 2000 22:01:52 EDT." <Pine.BSF.4.21.0006302200040.4585-100000@picnic.mat.net> References: <Pine.BSF.4.21.0006302200040.4585-100000@picnic.mat.net>
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> On Fri, 30 Jun 2000, Garance A Drosihn wrote: > > > At 9:04 PM -0400 6/28/00, Chuck Robey wrote: > > >On Wed, 28 Jun 2000, Will Andrews wrote: > > > > > > > On Tue, Jun 27, 2000 at 02:41:27AM -0700, John Baldwin wrote: > > > > > Erm, then why not do this with apsfilter? > > > > > > > > Because apsfilter also brings in far more useless junk that > > > > LPRng does. 26,000 lines over our current lpr == LPRng. > > > > apsfilter == LPRng + lots and lots and lots of other crap. > > > > > >I'm curious about that. How does LPRng get gif to postscript > > >conversion without ghostscript (one of the biggest pieces of > > >"crap" you refer to). How does it get ascii (or any other > > >format) to postscript? > > > > I'm a bit spaced out right now, but offhand I don't see why > > ghostscript would be needed for converting anything (except > > PDF) into postscript. I suspect apsfilter only uses it for > > printing postscript jobs on non-postscript printers, or for > > doing clever manipulation of postscript (for page-counting, > > perhaps). I would be inclined to use something like netpbm > > to get GIF images INTO postscript. Not ghostscript. > > Were you aware that most of the netpbm things that go into postscript CALL > ghostscript? In fact, since you say you've been printing jpegs and gifs > for a long time, go a look (a closer one) at the executeables you've been > using. How do they do it? This can't be right. ghostscript is a PostScript interpreter, which takes as input a PostScript program. It executes the PostScript program, which usually as a side-effect causes an image to be rendered, usually in the form of a bitmap, for each page. Then that bitmap is squirted out to a printer than doesn't have it's own PostScript interpreter. To convert a JPEG, GIF or PNM bitmap into PostScript is at it's core a simply syntatic excercise. You produce the uncompressed bitmap from the input source by un-doing any compression according to the method associated with the file format. Ghostscript is not involved in this process. You then emit the bitmap along with some idomatic PostScript code, which included the image operator, which causes a PostScript printer to print the bitmap on the page (as compared to using the show operator to render a font on the page). I'm very familiar with the latter phase of this, as many year ago I wrote a DVI to PostScript converter program which converts many tiny bitmaps into a PostScript program to be rendered (usually on a PostScript printer). Now, a filter which claims to take a PostScript program as input would quite likely need ghostscript (or some other PostScript interpeter) to compute a bitmap for the netpbm tools to operate on. Perhaps this is what you had in mind? louie To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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