.TH RESAMPLE 9.1
.SH NAME
resample, pdup \- resample a picture
.SH SYNOPSIS
.B fb/resample
.I width
[
.I input
] [
.I B
.I C
]
.PP
.B fb/pdup
.I sx sy
[
.I input
]
.SH DESCRIPTION
.I Resample
resamples the scan lines of its input image (default standard input)
to the given new width.  The image is decimated or interpolated using
a well-designed cubic filter.
See
.IR transpose (9.1)
for assistance with vertical resampling.
.PP
The reference explains the optional filter parameters
.I B
and
.IR C .
The default values give optimal alias rejection, and should not
normally be tampered with.
.PP
.I Pdup
scales an image by pixel duplication.
.I Sx
and
.I sy
are the horizontal and vertical scale factors.  They must be
positive integers.  In the output image (written on standard output),
each pixel of the input image (default standard input) generates an
.I sx×sy
block of identical pixels.
.SH SOURCE
.B /sys/src/fb/resample.c
.br
.B /sys/src/fb/pdup.c
.SH "SEE ALSO
.IR picfile (9.6),
Don P. Mitchell and Arun Netravali,
``Reconstruction in Computer Graphics'',
.I
SIGGRAPH '88 Conference Proceedings.