NAME
ra_ps - convert RADIANCE picture to a PostScript file
SYNOPSIS
ra_ps [ -b|c ][ -A|B|C ][ -n ncopies ][ -e +/-stops ][ -g gamma ][ -p
paper ][ -m[h|v] margin ][ -d dpi ] [ input [ output ] ]
DESCRIPTION
Ra_ps translates a RADIANCE picture to a color or greyscale Adobe
PostScript file for printing on a laser printer or importing to a page
layout program. The -b option tells ra_ps to produce greyscale output.
(The default is color, which may be specified explicitly with the -c
option.)
The -A option specifies that the output should be in uncompressed ASCII
hexstring format (the default). The -B option specifies that the
output should be in uncompressed binary string format. The file size
will be roughly half that of the ASCII equivalent, but some printers
and especially some printer connections do not support binary transfer,
so this option should be used with caution. The -C option specifies
that the output should be in run-length compressed ASCII format. The
file size will be one half to one tenth as large as the hexstring
equivalent and can be sent over any network or by e-mail. The only
disadvantage is that it will actually take longer to print on some
printers, since the "readhexstring" procedure is generally faster than
a custom replacement.
The -n option specifies the number of copies to print of this image.
It is often preferable to use this option instead of the multiple copy
option of the print spooler program, since the latter often results in
duplication of the input file with a large associated cost.
The -e option specifies an exposure compensation in f-stops (powers of
two). Only integer stops are allowed, for efficiency. The -g option
specifies a power law for the printer transfer function. The default
gamma setting for greyscale printers is 1.0 (linear), and the default
gamma for color printers is 1.8 (commonly used in prepress). If your
output seems to have too much contrast relative to its screen
equivalent, print out the file "ray/lib/lib/gamma.hdr" to your printer
without any gamma correction and using the -d option to set the dots-
per-inch (see below). The best match between the small lines and the
grey patch next to it indicate the approximate gamma of your printer,
which you should use with the -g option for best contrast reproduction
in subsequent conversions.
The standard print area assumes 8.5 by 11 inch (U.S. letter) paper,
with 0.5 inch margins on all sides. The image will be rotated 90
degrees if it fits better that way in the available print area, and it
will always be centered on the page. The -p and -m options to control
the paper size and margins, respectively. The argument to the -p
option is the common name for a given paper size, or WWxHH, where WW is
the width (in inches) and HH is the height. If millimeters or
centimeters are the preferred measurement unit, the ’x’ may be replaced
by ’m’ or ’c’, respectively. The WW and HH values are decimal
quantities, of course. The current paper identifiers understood by the
program may be discovered by giving a 0 argument to the -p option.
They are currently:
_Name________Width_Height_(inches)
envelope 4.12 9.50
executive 7.25 10.50
letter 8.50 11.00
lettersmall 7.68 10.16
legal 8.50 14.00
monarch 3.87 7.50
statement 5.50 8.50
tabloid 11.00 17.00
A3 11.69 16.54
A4 8.27 11.69
A4small 7.47 10.85
A5 6.00 8.27
A6 4.13 6.00
B4 10.12 14.33
B5 7.17 10.12
C5 6.38 9.01
C6 4.49 6.38
DL 4.33 8.66
hagaki 3.94 5.83
The paper size name may be abbreviated with three or more letters, and
character case is ignored. The argument to the -m option is the margin
width, which is 0.5 inches by default. A millimeter or centimeter
quantity may be given instead of inches by immediately following the
value with a ’m’ or ’c’ character, respectively. (Leave no space
between the quantity and its unit letter.) If you wish to specify the
horizontal and vertical margins separately, use the -mh and -mv
options, instead.
The -d option may be used to explicitly set the print density (in dots
per inch). If the input picture is lower resolution than the printer
and has square pixels, then ra_ps will adjust the image size so that
pixels map to dot regions exactly. This may improve the appearance of
fine detail, and may speed up the printing process as well, at the
expense of a slightly smaller image area. If you wish to maximize
print area and the input image contains no fine detail, then do not
specify this option.
The output from ra_ps is designed to be compatible with the
Encapsulated PostScript standard, which means that the resulting file
may be incorporated into documents by page layout programs that can
read in EPS files. Unfortunately, there is currently no option for
generating a preview bitmap, so the image will show up on the screen as
a rectangular area only. To control the EPS image size directly, use
the -p option as explained above with the WWxHH specification, and set
-m 0 to turn off the margins.
AUTHOR
Greg Ward
SEE ALSO
pfilt(1), ra_bmp(1), ra_bn(1), ra_pr(1), ra_pr24(1), ra_t8(1),
ra_t16(1), ra_ppm(1), ra_tiff(1), ximage(1)