Printing greyscale images ?

Printing greyscale images ?

Post by Mark Oles » Fri, 05 Nov 1993 22:40:22


I have nominally 640x480 - 256 greyscale images (pgm format) that I wish
to print on an HP LaserJet IIP (no postscript).

Currently my only recourse is to use something like the following:
  pgmtopbm file.pgm | pbmtolj -resolution [75|100|150|300] > output.prn

This works fine, except the quality is not very good; ie., a 600x300 image
printed at 300dpi yields a 2x1 inch image, whilst printing at 75dpi yields
an 8x4 inch image with dots that are four times as large.

What, if any, PD software is there for printing greyscale images (PGM |
BMP | GIF) for MS/DOS | UNIX on an HP LaserJet IIP?  I am also open to
printer suggestions.

Thanks for whatever assistance,

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Printing greyscale images ?

Post by Paul Chamberla » Sun, 07 Nov 1993 03:42:39



>Currently my only recourse is to use something like the following:
>  pgmtopbm file.pgm | pbmtolj -resolution [75|100|150|300] > output.prn
>This works fine, except the quality is not very good; ie., a 600x300 image
>printed at 300dpi yields a 2x1 inch image, whilst printing at 75dpi yields
>an 8x4 inch image with dots that are four times as large.

How about something like:
pnmscale 5 file.bgm | pgmtopbm | pbmtolj -resolution 300 > output.prn
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Printing greyscale images ?

Post by Roy Johns » Sun, 07 Nov 1993 05:40:12



> I have nominally 640x480 - 256 greyscale images (pgm format) that I wish
> to print on an HP LaserJet IIP (no postscript).
> Currently my only recourse is to use something like the following:
>   pgmtopbm file.pgm | pbmtolj -resolution [75|100|150|300] > output.prn
> This works fine, except the quality is not very good; ie., a 600x300 image
> printed at 300dpi yields a 2x1 inch image, whilst printing at 75dpi yields
> an 8x4 inch image with dots that are four times as large.

So scale the image up before converting to pbm:

pnmenlarge 4 file.pgm | pgmtopbm | pbmtolj -res 300 > output.prn
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