The package img::ps is a sub-package of
Img. It can be loaded as a part of the
complete Img support, via package require Img,
or on its own, via package require img::ps.
Like all packages of Img it does
not provide new commands, but extends the existing Tk command image so that it supports files containing raster
images in the Adobe PostScript Format (ps). More specifically img::ps extends Tk's photo image
type.
The name of the new format handler is ps.
This handler provides new additional configuration options. See
section PostScript
OPTIONS for more detailed explanations.
Note that this package provides a pdf
handler too, i.e. a handler for the Adobe Portable Document Format.
That handler accepts the same options as the ps handler.
The package delegates the actual conversion of data in
PostScript and PDF format into a raster image to the ghostscript
application. It therefore depends upon the presence of said
application and is non-functional is ghostscript is not present.
Image data in ps and PDF format (options -data and -file) is detected
automatically.
The format names ps and pdf are recognized by the option -format. In addition the value for the option is
treated as list and may contain any of the special options listed
in section PostScript
OPTIONS.
The handler provides two options, both influencing the reading
of PostScript or PDF images. The handler is not able to
write images in PostScript or PDF.
-indexn
This option is for reading from PostScript/PDF data containing
more than one page. When specified it will read the n'th page in the data. The first page is at index 0 and will be read by default, i.e. when the
option is not specified.
Note: This option is not yet implemented.
-zoomXY
Multiply image size by the given scale factors. If Y is missing, the default is the same as X. X and Y are
allowed to be in floating point format, but they are rounded to the
nearest practically possible value. For postscript this means the
zoom factors should be multiples of 1/72.
The code provided by Img does not perform the interpretation and
rasterizing of the input by itself but delegates this to the gs application.
This is the GhostScript implementation of PostScript (and PDF).
If gs is
not installed this format handler cannot be used.