libwebp/man/img2webp.1
James Zern b6f756e82b update http links
- prefer https

- metadataworkinggroup.org/com seem to be offline; the web archive link
  was obtained from exiftool: https://exiftool.org/TagNames/MWG.html

- fix kramdown link, rubyforge has been gone a long time

- fix png/zlib links

Bug: webp:544
Bug: b/202302177
Change-Id: Id69de4553e7baf00393f12a2c1acb262443a1a93
2021-11-23 10:13:40 -08:00

106 lines
3.3 KiB
Groff

.\" Hey, EMACS: -*- nroff -*-
.TH IMG2WEBP 1 "November 17, 2021"
.SH NAME
img2webp \- create animated WebP file from a sequence of input images.
.SH SYNOPSIS
.B img2webp
[file_level_options] [files] [per_frame_options...]
.br
.B img2webp argument_file_name
.br
.SH DESCRIPTION
This manual page documents the
.B img2webp
command.
.PP
\fBimg2webp\fP compresses a sequence of images using the animated WebP format.
Input images can either be PNG, JPEG, TIFF or WebP.
If a single file name (not starting with the character '\-') is supplied as
the argument, the command line arguments are actually tokenized from this file.
This allows for easy scripting or using a large number of arguments.
.SH FILE-LEVEL OPTIONS
The file-level options are applied at the beginning of the compression process,
before the input frames are read.
.TP
.BI \-o " string
Specify the name of the output WebP file.
.TP
.BI \-min_size
Encode images to achieve smallest size. This disables key frame insertion and
picks the parameters resulting in the smallest output for each frame. It uses
lossless compression by default, but can be combined with \-q, \-m, \-lossy or
\-mixed options.
.TP
.BI \-kmin " int
.TP
.BI \-kmax " int
Specify the minimum and maximum distance between consecutive key frames
(independently decodable frames) in the output animation. The tool will insert
some key frames into the output animation as needed so that this criteria is
satisfied.
.br
.B \-mixed
Mixed compression mode: optimize compression of the image by picking either
lossy or lossless compression for each frame heuristically. This global
option disables the local option \fB-lossy\fP and \fB-lossless\fP .
.TP
.BI \-loop " int
Specifies the number of times the animation should loop. Using '0'
means 'loop indefinitely'.
.TP
.BI \-v
Be more verbose.
.TP
.B \-h, \-help
A short usage summary.
.TP
.B \-version
Print the version numbers of the relevant libraries used.
.SH PER-FRAME OPTIONS
The per-frame options are applied for the images following as arguments in the
command line. They can be modified any number of times preceding each particular
input image.
.TP
.BI \-d " int
Specify the image duration in milliseconds.
.TP
.B \-lossless, \-lossy
Compress the next image(s) using lossless or lossy compression mode. The
default mode is lossless.
.TP
.BI \-q " float
Specify the compression factor between 0 and 100. The default is 75.
.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.
.SH EXAMPLE
img2webp -loop 2 in0.png -lossy in1.jpg -d 80 in2.tiff -o out.webp
.br
.SH BUGS
Please report all bugs to the issue tracker:
https://bugs.chromium.org/p/webp
.br
Patches welcome! See this page to get started:
https://www.webmproject.org/code/contribute/submitting\-patches/
.SH AUTHORS
\fBimg2webp\fP is a part of libwebp and was written by the WebP team.
.br
The latest source tree is available at
https://chromium.googlesource.com/webm/libwebp
.PP
This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>,
for the Debian project (and may be used by others).
.SH SEE ALSO
.BR webpmux (1),
.BR gif2webp (1)
.br
Please refer to https://developers.google.com/speed/webp/ for additional
information.