.TH POSTER 1
.fi
.SH NAME
poster \- Scale and tile a postscript image to print on multiple pages
.SH SYNOPSIS
.in +7n
.ti -7n
poster <options> infile
.in -7n
.SH DESCRIPTION
\fIPoster\fP can be used to create a large poster by building it
from multiple pages and/or printing it on large media.
It expects as input a generic (encapsulated) postscript
file, normally printing on a single page.
The output is again a postscript file, maybe containing multiple pages
together building the poster.
The output pages bear cutmarks and have slightly overlapping images
for easier assembling.
The input picture will be scaled to obtain the desired size.
.P
The program uses a brute-force method: it copies the entire input
file for each output page, hence the output file can be very large.
Since the program does not really bother about the input file contents,
it clearly works for both black-and-white and color postscript.
.P
To control its operation, you need to specify either the size
of the desired poster or a scale factor for the image:
.TP 2n
-
Given the poster size, it calculates the required number of sheets
to print on, and from that a scale factor to fill these sheets optimally with the
input image.
.TP
-
Given a scale factor, it derives the required number of pages from the input
image size, and positions the scaled image centered on this area.
.P
Its input file should best be a real `Encapsulated Postscript' file
(often denoted with the extension .eps or .epsf).
Such files can be generated from about all current drawing applications,
and text processors like Word, Interleaf and Framemaker.
.br
However \fIposter\fP tries to behave properly also on more relaxed,
general postscript files containing a single page definition.
Proper operation is obtained for instance on pages generated
by (La)TeX and (g)troff.
.P
The media to print on can be selected independently from the input image size
and/or the poster size. \fIPoster\fP will determine by itself whether it
is beneficial to rotate the output image on the media.
.P
To preview the output results of \fIposter\fP and/or to (re-)print individual
output pages, you should use a postscript previewer like ghostview(1).

.ne 5
.SH OPTIONS
.TP 3n
-v
Be verbose. Tell about scaling, rotation and number of pages.
.br
Default is silent operation.
.TP
-f
Ask manual media feed on the plotting/printing device,
instead of using its standard paper tray.
.br
Default is adhering to the device settings.
.TP
-i <box>
Specify the size of the input image.
.br
Default is reading the image size from the `%%BoundingBox' specification
in the input file header.
.TP
-m <box>
Specify the desired media size to print on. See below for <box>.
.br
The default is obtained from the PAPERCONF environment variable.  If
it is not set, it is read from the file whose name is in the PAPERSIZE
environment variable.  If that too is not set, the default is read
from the file /etc/papersize.  See
.BR papersize (5)
for a full description of the format of the config file.
.TP
-p <box>
Specify the poster size. See below for <box>.
Since \fIposter\fP will autonomously choose for rotation,
always specify a `portrait' poster size (i.e. higher then wide).
.br
If you don't give the -s option, the default poster size is identical to the
media size.
.TP
-s <number>
Specify a linear scaling factor to produce the poster.
Together with the input image size and optional margins, this induces
an output poster size. So don't specify both -s and -p.
.br
Default is deriving the scale factor to fit a given poster size.
.TP
-c <box> \fIor\fP -c <number>%
.br
Specify the cut margin. This is the distance between the cutmarks and
the paper edge. If the output is really tiled on multiple sheets,
the cut marks indicate where to cut the paper for assembly.
This margin must be big enough to cover the non-printable margin which almost
all printers have. For <box> see below.
.br
Default is 5%. Only when you specify identical poster and media sizes,
the default cut margin becomes 0, effectively removing the cutmarks.
.TP
-w <box> \fIor\fP -w <number>%
.br
Specify a white margin around the output image.
.br
In the `ideal' situation (when an input `eps' file specifies an exact
BoundingBox in its header), the output image will be scaled exactly to
the edges of the resulting poster (minus cut margin). If you desire
a certain margin to remain around the picture after poster assembly,
you can specify this with `-w'.
.br
(This option is actually redundant, since you can obtain the same result
using -s or -i. However some might find this more convenient.)
.br
Default is 0.
.TP
-P <pagespec>
.br
Specify which pages of the poster to print. It consists of a comma-separated
list of single pages or page ranges (using the dash). The order in which
page number appears determines the final page order in the result PostScript
file. Page numbering starts at 1, from left to right and bottom-up.
.br
Examples: 1-2 or 1,3-4,7
.TP
-o <outputfile>
Specify the name of the file to write the output into.
.br
(Only added for those poor people who cannot specify output redirection
from their command line due to a silly OS.)
.br
Default is writing to standard output.
.P
The <box> mentioned above is a specification of horizontal and vertical size.
Only in combination with the `-i' option, the program also understands the
offset specification in the <box>.
.br
In general:
     <box> = [<multiplier>][<offset>]<unit>
.br
with multipier and offset being specified optionally.
     <multiplier> = <number>*<number>
.br
     <offset> = +<number>,<number>
.br
     <unit> = <medianame> or <distancename>
.P
Many international media names are recognised by the program, in upper and lower case,
and can be shortened to their first few characters, as long as unique.
For instance `A0', `Let'.
.br
Distance names are like `cm', `i', `ft'.

.ne 5
.SH EXAMPLES
The following command prints an A4 input file on 8 A3 pages, forming an A0
poster:
         poster -v -iA4 -mA3 -pA0 infile >outfile

.ne 3
The next command prints an eps input image on a poster of 3x3 Letter pages:
         poster -v -mLet -p3x3Let  image.eps > outfile

.ne 3
The next command enlarges an eps input image to print on a
large-media A0 capable device, maintaining 2 inch margins:
         poster -v -mA0 -w2x2i image.eps > outfile

.ne 3
Enlarge a postscript image exactly 4 times, print on the default A4 media,
and let \fIposter\fP determine the number of pages required:
         poster -v -s4 image.eps > outfile

.ne 6
Scale a postscript image to a poster of about 1 square meter, printing
on `Legal' media, maintaining a 10% of `Legal' size as white margin
around the poster.
         poster -v -mLegal -p1x1m -w10% infile.ps >outfile

.ne 5
.SH "PROBLEMS & QUESTIONS"
.SS "I get a blurry image and/or interference patterns"
If your input file contains -or consists of- pixel images (as opposed
to just vector data which is essentially resolution independent),
you might have this problem.
Such pixel images are normally made to fit well to standard 300 (or 600) dpi devices.
Scaling such a picture with an uncarefully chosen factor,
can easily lead to hazy edges and interference patterns on the output.
The solution is to provide \fIposter\fP with an exact scaling factor
(with the -s option), chosen as an integer. If integer scaling is
unpractical for your purpose,
choose a fractional number made from a small integer denominator (2, 3, 4).
.SS "Can I select only a small part of a given input picture?"
Yes, for this purpose you can define both the size (width and height)
and offset (from left and bottom) of a window on the input image.
Specify these numbers as argument to a `-i' command line option.
.br
One way to obtain such numbers is previewing the original image with
ghostview,
and observing the coordinate numbers which it continually displays.
These numbers are in postscript units (points),
named by \fIposter\fP as just `p'.
.SS "Poster doesn't seem to work properly, output pages are empty"
The major cause for poster not to work correctly, is giving it
postscript files which don't conform to proper 'eps' behaviour.
Try whether your application (or printer driver) cannot generate
real 'encapsulated postscript'.
.SS "If I ask for a 50x50cm poster, it always generates something bigger"
Yes, probably. When specifying a desired output size with the `-p' option,
\fIposter\fP first determines an array of sheets to cover such an area.
Then it determines a scale factor for the picture to fill these sheets upto
their edge. As result your requested size is used as rough guess only.
If you want an exact output size, specify the scaling factor yourself
with the `-s' option (and omit the `-p').
.SS "I want to keep the white space around the poster as in my original"
\fIPoster\fP will as default use the input image bounding box, and
scale/translate that to the edges of your poster.
If the program which generated your input file specifies an exact and tight
%%BoundingBox, you will indeed loose your white margin.
To keep the original margin, specify a `-i' option with as argument the papersize
on which the original document was formatted (such as `-iA4').
Alternatively specify a smaller scale factor (with -s) or an explicit new
margin (with -w).

.ne 4
.SH "POSTER ASSEMBLY"
Our preferred method for the assembly of a poster from multiple sheets
is as follows:
.TP 2n
-
Arrange the sheets in the proper order on a large table or on the floor.
.TP
-
Remove from all sheets, except from those in the leftmost column or
bottom row, their left and bottom cutmargin.
.TP
-
In left-to-right and bottom-to-top order, glue the right (and top) cutmargin
and stick the right (and upper) neighbouring page on top of that.
.TP
-
Turn the glued-together poster face bottom, and put adhesive tape on the sheet
edges (on the backside of the poster) for more strength.
.TP
-
Remove the remaining cutmargin around the poster.

.ne 4
.SH "DEVICE SETTINGS"
For postscript level-2 capable printers/plotters, which is about all modern postscript
devices today, \fIposter\fP will send device settings in its output file.
This consists of a `setpagedevice' call, setting:
.TP 2n
-
the media size.
.br
This is required for all printers I know to get correct
behaviour on different media/picture sizes.
.TP
-
duplexing off.
.br
Some printers will otherwise perform double-side printing by default.
Clearly that is not what you want to print a poster.
.TP
-
manual media feed.
.br
This is given only when \fIposter\fP was executed with the `-f'
command line option. This is a convenient feature if you want to print
your job on different media than normally installed in the paper tray,
and you are submitting your job through a multi-user networking and
spooling environment.
.P
These settings cause proper device behaviour, without the need to
manually interact with the printer settings, and has been here locally
tested to work on devices like the HP300XL and HP650C.
.P
The settings thus passed in the postscript file, will affect the device
for this job only.
 
.SH "DSC CONFORMANCE"
\fIPoster\fP will generate its own DSC header and other DSC lines
in the output file, according the `Document Structuring Conventions - version
3.0',
as written down in the `Postscript Language Reference Manual, 2nd ed.' from
Adobe Systems Inc, Addison Wesley Publ comp., 1990.
.P
It will copy any `%%Document...' line from the input file DSC header to its
own header output. This is used here in particular for required nonresident
fonts.
.P
However the copy(s) of the input file included in the output,
are stripped from all lines starting with a `%', since they tend to
disturb our `ghostview' previewer and take useless space anyhow.

.SH "SEE ALSO"
.BR ghostview "(1), " papersize (5)

.SH "CONTRIBUTED BY"
.nf
.na
Jos van Eijndhoven (email: J.T.J.v.Eijndhoven@ele.tue.nl)
Design Automation Section (http://www.es.ele.tue.nl)
Dept. of Elec. Eng.
Eindhoven Univ of Technology
The Netherlands
24 August, 1995