els.


SYNOPSIS
pamstretch

[-xscale=X]

[-yscale=Y] [-blackedge]

[-dropedge]

N

[infile]

You can use the minimum unique abbreviation of the options. You can
use two hyphens instead of one. You can separate an option name from
its value with white space instead of an equals sign.


DESCRIPTION
This program is part of Netpbm.

pamstretch scales up pictures by integer values, either vertically,
horizontally, or both. pamstretch differs from pamscale and pamen-
large in that when it inserts the additional rows and columns, instead
of making the new row or column a copy of its neighbor, pamstretch
makes the new row or column an interpolation between its neighbors.
In some images, this produces better looking output.

To scale up to non-integer pixel sizes, e.g. 2.5, try pamstretch-
geninstead.

Options let you select alternative methods of dealing with the
right/bottom edges of the picture. Since the interpolation is done
between the top-left corners of the scaled-up pixels, it's not obvious
what to do with the right/bottom edges. The default behaviour is to
scale those up without interpolation (more precisely, the right edge
is only interpolated vertically, and the bottom edge is only interpo-
lated horizontally), but there are two other possibilities, selected
by the blackedge and dropedge options.


PARAMETERS
The N parameter is the scale factor. It is valid only if you don't
specify -xscale or -yscale. In that case, pamstretch scales in both
dimensions and by the scale factor N.


OPTIONS
-xscale=X


-yscale=Y


-blackedge


-dropedge




BUGS
Usually produces fairly ugly output for PBMs. For most PBM input
you'll probably want to reduce the 'noise' first using something like
pnmnlfilt.


SEE ALSO
pamstretch-gen, pamenlarge, pamscale, pnmnlfilt


AUTHOR
Russell Marks (russell.marks@ntlworld.com).



netpbm documentation 11 November 2001 Pamstretch User Manual(0)