All options can be abbreviated to their shortest unique prefix. You may
use two hyphens instead of one. You may separate an option name and its
value with white space instead of an equals sign.
If you specify no output dimensioning options, the output image is
dimensioned as if you had specified
-scale=1.0,
which means aproximately 72 pixels of the input image generate one
inch of output (if that fits the page).
- -imagewidth
-
-imageheight
Tells how wide and high you want the image on the page, in inches.
The aspect ratio of the image is preserved, so if you specify both of these,
the image on the page will be the largest image that will fit within the
box of those dimensions.
If these dimensions are greater than the page size, you get Postscript
output that runs off the page.
You cannot use
imagewidth
or
imageheight
with
-scale
or
-equalpixels.
- -equalpixels
-
This option causes the output image to have the same number of pixels
as the input image. So if the output device is 600 dpi and your image
is 3000 pixels wide, the output image would be 5 inches wide.
You cannot use
-equalpixels
with
-imagewidth,
-imageheight,
or
-scale.
- -scale
-
tells how big you want the image on the page. The value is the number of
inches of output image that you want 72 pixels of the input to generate.
But
pnmtops
rounds the number to something that is an integral number of output
device pixels. E.g. if the output device is 300 dpi and you specify
-scale=1.0,
then 75 (not 72) pixels of input becomes one inch of output (4 output
pixels for each input pixel). Note that the
-dpi
option tell
pnmtops
how many pixels per inch the output device generates.
If the size so specified does not fit on the page (as measured either
by the
-width
and
-height
options or the default page size of 8.5 inches by 11 inches),
pnmtops
ignores the
-scale
option, issues a warning, and scales the image to fit on the page.
- -dpi
-
This option specifies the dots per inch of your output device. The
default is 300 dpi. In theory PostScript is device-independent and
you don't have to worry about this, but in practice its raster
rendering can have unsightly bands if the device pixels and the image
pixels aren't in sync.
Also this option is crucial to the working of the
equalpixels
option.
- -width
-
-height
These options specify the dimensions of the page on which the output is
to be printed. This can affect the size of the output image.
The page size has no effect, however, when you specify the
-imagewidth,
-imageheight,
or
-equalpixels
options.
These options may also affect positioning of the image on the page and
even the paper selected (or cut) by the printer/plotter when the
output is printed. See the
-nosetpage
option.
The default is 8.5 inches by 11 inches.
- -turn
-
-noturn
These options control whether the image gets turned 90 degrees.
Normally, if an image fits the page better when turned (e.g. the image
is wider than it is tall, but the page is taller than it is wide), it
gets turned automatically to better fit the page. If you specify the
-turn
option,
pnmtops
turns the image no matter what its shape; If you specify
-noturn,
pnmtops
does
not
turn it no matter what its shape.
- -rle
-
-runlength
These identical options specify run-length compression. This may save
time if the host-to-printer link is slow; but normally the printer's
processing time dominates, so
-rle
makes things slower.
- -nocenter
-
By default,
pnmtops
centers the image on the output page.
You can cause
pnmtops
to instead put the image against the upper left corner of the page with
the
-nocenter
option. This is useful for programs which can include
PostScript files, but can't cope with pictures which are not
positioned in the upper left corner.
For backward compatibility,
pnmtops
accepts the option
-center,
but it has no effect.
- -setpage
-
pnmtops
can generate a "setpagedevice" directive to tell the
printer/plotter what size paper to use (or cut). The dimensions it specifies
on this directive are those selected or defaulted by the
width
and
height
options or defaulted. If you want a "setpagedevice" directive in the
output, specify
-setpage.
This can be useful if your printer chokes on this directive, which has not
always been defined in Postscript, or you want to fake out the printer and
print on one size paper as if you're printing on another.
Before release 10.0 the default was to generate the "setpagedevice" directive,
and there is the switch
-nosetpage
to supress it, but that's actually a no-op now.