harvey/sys/man/1/resample

.TH RESAMPLE 1
.SH NAME
resample \- resample a picture
.SH SYNOPSIS
.B resample
[
.B -x
.I size
] [
.B -y
.I size
] [
.I file
]
.SH DESCRIPTION
.I Resample
resamples its input image (default standard input) to a new size.
The image is decimated or interpolated using
a Kaiser window.
.PP
The size of the resampled image can be specified
with the
.B -x
and
.B -y
options.
An unadorned value sets the number of pixels of that dimension; a suffixed percent sign specifies a percentage.
If only one of
.B -x
or
.B -y
is given, the other dimension is scaled to preserve
the aspect ratio of the original image.
Thus,
.B -x50%
will reduce the image to half its original dimension in both
.B x
and
.BR y .
.PP
The input should be a Plan 9 image
as described in 
.IR image (6),
and the output will be a compressed 24-bit
.B r8g8b8
image.
To uncompress the image or change the pixel format, use
.I iconv
(see
.IR crop (1)).
.PP
.SH SOURCE
.B /sys/src/cmd/resample.c
.SH "SEE ALSO
.IR crop (1),
.IR image (6)
.SH BUGS
Faster algorithms exist, but this implementation produces correct pictures.