libwebp/man/gif2webp.1

.\"                                      Hey, EMACS: -*- nroff -*-
.TH GIF2WEBP 1 "February 01, 2013"
.SH NAME
gif2webp \- Convert a GIF image to WebP
.SH SYNOPSIS
.B gif2webp
.RI [ options ] " input_file.gif \-o output_file.webp
.br
.SH DESCRIPTION
This manual page documents the
.B gif2webp
command.
.PP
\fBgif2webp\fP converts a GIF image to a WebP image.
.SH OPTIONS
The basic options are:
.TP
.BI \-o " string
Specify the name of the output WebP file. If omitted, \fBgif2webp\fP will
perform conversion but only report statistics.
.TP
.B \-h, \-help
Usage information.
.TP
.B \-version
Print the version number (as major.minor.revision) and exit.
.TP
.B \-lossy
Encode the image using lossy compression.
.TP
.BI \-q " float
Specify the compression factor for RGB channels between 0 and 100. The default
is 75.
.br
In case of lossless compression (default), a small factor enables faster
compression speed, but produces a larger file. Maximum compression is achieved
by using a value of 100.
.br
In case of lossy compression (specified by the \-lossy option), a small factor
produces a smaller file with lower quality. Best quality is achieved by using a
value of 100.
.TP
.BI \-m " int
Specify the compression method to use. This parameter controls the
trade off between encoding speed and the compressed file size and quality.
Possible values range from 0 to 6. Default value is 4.
When higher values are used, the encoder will spend more time inspecting
additional encoding possibilities and decide on the quality gain.
Lower value can result is faster processing time at the expense of
larger file size and lower compression quality.
.TP
.BI \-kmax " int
Relevant only for animated images with large number of frames (>50).
Specify the maximum distance between consecutive key frames (independently
decodable frames) in the output image. The tool will insert some key frames into
the output image as needed so that this criteria is satisfied. A value of 0 will
turn off insertion of key frames.
Typical values are in the range 5 to 30. Default value is 9.
When lower values are used, more frames will be converted to key frames. This
may lead to smaller number of frames required to decode a frame on average,
thereby improving the decoding performance. But this may lead to slightly bigger
file sizes.
Higher values may lead to worse decoding performance, but smaller file sizes.
.TP
.BI \-f " int
For lossy encoding only (specified by the \-lossy option). Specify the strength
of the deblocking filter, between 0 (no filtering) and 100 (maximum filtering).
A value of 0 will turn off any filtering. Higher value will increase the
strength of the filtering process applied after decoding the picture. The higher
the value the smoother the picture will appear. Typical values are usually in
the range of 20 to 50.
.TP
.B \-v
Print extra information.
.TP
.B \-quiet
Do not print anything.

.SH BUGS
Please report all bugs to our issue tracker:
http://code.google.com/p/webp/issues
.br
Patches welcome! See this page to get started:
http://www.webmproject.org/code/contribute/submitting-patches/

.SH EXAMPLES
gif2webp picture.gif \-o picture.webp
.br
gif2webp \-q 70 picture.gif \-o picture.webp
.br
gif2webp \-lossy \-m 3 picture.gif \-o picture_lossy.webp
.br
gif2webp \-lossy \-f 50 picture.gif \-o picture.webp

.SH AUTHORS
\fBgif2webp\fP was written by the WebP team.
.br
The latest source tree is available at http://www.webmproject.org/code
.PP
This manual page was written by Urvang Joshi <urvang@google.com>, for the
Debian project (and may be used by others).

.SH SEE ALSO
.BR dwebp (1),
.BR cwebp (1),
.BR webpmux (1).
.br
Please refer to http://developers.google.com/speed/webp/ for additional
information.