If the input file is in color (PPM), a color PostScript file gets written. Some PostScript interpreters can't handle color PostScript. If you have one of these you will need to run your image through ppmtopgm first.
Note that there is no pstopnm tool - this transformation is one-way, because a pstopnm tool would be a full-fledged PostScript interpreter, which is beyond the scope of this package. However, see the psidtopgm tool, which can read grayscale non-runlength PostScript image data. Also, if you're willing to install the fairly large GhostScript package, it comes with a pstoppm script.
The -scale flag controls the scale of the result. The default scale is 1, which on a 300 dpi printer such as the Apple LaserWriter makes the output look about the same size as the input would if it was displayed on a typical 72 dpi screen. To get one PNM pixel per 300 dpi printer pixel, use "-scale 0.25".
The -turn and -noturn flags control whether the image gets turned 90 degrees. Normally, if an image is wider than it is tall, it gets turned automatically to better fit the page. If the -turn flag is specified, it will be turned no matter what its shape; and if the -noturn flag is specified, it will not be turned no matter what its shape.
The -rle or -runlength flag specifies 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.
The -dpi flag lets you specify 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.
The -width and -height flags let you specify the size of the page. The default is 8.5 inches by 11 inches.
With the -nocenter flag, the output is not centered on the page, i.e. it appears in the upper left corner. 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. The default is -center i.e. the image is centered on the page.
All flags can be abbreviated to their shortest unique prefix.
Created by unroff & hp-tools. © by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97