chaim@taux01.nsc.com (Chaim Bendelac) (11/27/90)
A typical 300dpi laser printer requires about 1Mb of memory to record the generated bitmap. Higher resolutions, larger pages, color or a combination of these drive a need for huge memory requirements. "Banding" is used in PCL-type printers to reduce the need for an entire bitmap: the next band is generated on the fly, while the laser-engine strokes the previous band. Strangely enough, I have never heard of banded PostScript. Why? What are the technological difficulties in banding a PostScript display-list? Are there unsolved algorithmic challanges? Why has it never been attempted? -- Chaim Bendelac, National Semiconductor, chaim@nsc.nsc.com -- Regards, Chaim chaim@nsc.nsc.com, nsc(chaim) or CCBETA. 972-52-522255 or ...-455624 @ home
rberlin@birdland.sun.com (Rich Berlin) (11/28/90)
> Strangely enough, I have never heard of banded PostScript. Why? What are > the technological difficulties in banding a PostScript display-list? Are > there unsolved algorithmic challanges? Why has it never been attempted? Banding is the rendering method of choice in high-resolution phototypesetters. It's been used in PostScript rips for some time; if you look in the redbook on page 201, you'll see a definition of the `renderbands' operator.... -- Rich
rcj2@cbnewsd.att.com (ray.c.jender) (11/28/90)
In article <RBERLIN.90Nov27164719@birdland.sun.com>, rberlin@birdland.sun.com (Rich Berlin) writes: > > Strangely enough, I have never heard of banded PostScript. Why? What are > > the technological difficulties in banding a PostScript display-list? Are > > there unsolved algorithmic challanges? Why has it never been attempted? > > Banding is the rendering method of choice in high-resolution > phototypesetters. It's been used in PostScript rips for some time; if > you look in the redbook on page 201, you'll see a definition of the > `renderbands' operator.... > > -- Rich Could we be talking about two different bandings here? I thought the original post was talking about banding in the final output, you know those noticeable verticle lines in graphic printouts. This is also banding. I guess it could also be called banding when you don't have enough color transition's in a vignette....
gah@nntp-server.caltech.edu (Geln A. Herrmannsfeldt) (11/29/90)
t the reisk of repeating others, many higher resolution postscript devices do banding. There are even postscript operators for it. As an example, look at the linotronic L100 and L300. To do it, though, it must be possible to stop the writing to the outpur media. The linotronic advances the film only as much as necessary for each band. Xerographic printers usually cannot do this. .
david@marvin.jpl.oz (David Magnay) (12/05/90)
in article <5037@taux01.nsc.com>, chaim@taux01.nsc.com (Chaim Bendelac) says: > Strangely enough, I have never heard of banded PostScript. Why? What are > the technological difficulties in banding a PostScript display-list? Are > there unsolved algorithmic challanges? Why has it never been attempted? PS is not a rasterised language. It can generate output for any part of the page at any time in the document. Thus, it can only be "banded" after it has been rasterised. The 1M or so of RAM is the rasterising buffer ( save for the font caches). If the PS input could be constrained, your suggestion would work. However, that would upset the essential essence of what PS is all about.