plan9port/man/man1/resample.1
Russ Cox 977b25a76a tmac: introduce real manual reference macro instead of overloading IR
The overloading of IR emits magic \X'...' sequences that turn into HTML manual links.
But not all such IR invocations should be manual links;
those had to be written to avoid the IR macro before.
Worse, the \X'...' ending the IR causes troff to emit only a single space after a period.

Defining a new IM macro for manual references fixes both problems.

Fixes #441.
2020-08-13 23:43:43 -04:00

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.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
.IM image (7) ,
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
.IM crop (1) ).
.PP
.SH SOURCE
.B \*9/src/cmd/resample.c
.SH "SEE ALSO
.IM crop (1) ,
.IM image (7)
.SH BUGS
Faster algorithms exist, but this implementation produces correct pictures.