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man_MANS = cwebp.1 dwebp.1
if BUILD_MUX
man_MANS += webpmux.1
endif
if BUILD_GIF2WEBP
man_MANS += gif2webp.1
endif
if BUILD_IMG2WEBP
man_MANS += img2webp.1
endif
if BUILD_VWEBP
man_MANS += vwebp.1
endif
if BUILD_WEBPINFO
man_MANS += webpinfo.1
endif
EXTRA_DIST = $(man_MANS)

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.\" Hey, EMACS: -*- nroff -*-
.TH CWEBP 1 "March 17, 2022"
.SH NAME
cwebp \- compress an image file to a WebP file
.SH SYNOPSIS
.B cwebp
.RI [ options ] " input_file \-o output_file.webp
.br
.SH DESCRIPTION
This manual page documents the
.B cwebp
command.
.PP
\fBcwebp\fP compresses an image using the WebP format.
Input format can be either PNG, JPEG, TIFF, WebP or raw Y'CbCr samples.
Note: Animated PNG and WebP files are not supported.
.SH OPTIONS
The basic options are:
.TP
.BI \-o " string
Specify the name of the output WebP file. If omitted, \fBcwebp\fP will
perform compression but only report statistics.
Using "\-" as output name will direct output to 'stdout'.
.TP
.BI \-\- " string
Explicitly specify the input file. This option is useful if the input
file starts with a '\-' for instance. This option must appear \fBlast\fP.
Any other options afterward will be ignored.
.TP
.B \-h, \-help
A short usage summary.
.TP
.B \-H, \-longhelp
A summary of all the possible options.
.TP
.B \-version
Print the version number (as major.minor.revision) and exit.
.TP
.B \-lossless
Encode the image without any loss. For images with fully transparent area,
the invisible pixel values (R/G/B or Y/U/V) will be preserved only if the
\-exact option is used.
.TP
.BI \-near_lossless " int
Specify the level of near\-lossless image preprocessing. This option adjusts
pixel values to help compressibility, but has minimal impact on the visual
quality. It triggers lossless compression mode automatically. The range is 0
(maximum preprocessing) to 100 (no preprocessing, the default). The typical
value is around 60. Note that lossy with \fB\-q 100\fP can at times yield
better results.
.TP
.BI \-q " float
Specify the compression factor for RGB channels between 0 and 100. The default
is 75.
.br
In case of lossy compression (default), a small factor produces a smaller file
with lower quality. Best quality is achieved by using a value of 100.
.br
In case of lossless compression (specified by the \fB\-lossless\fP option), a
small factor enables faster compression speed, but produces a larger file.
Maximum compression is achieved by using a value of 100.
.TP
.BI \-z " int
Switch on \fBlossless\fP compression mode with the specified level between 0
and 9, with level 0 being the fastest, 9 being the slowest. Fast mode
produces larger file size than slower ones. A good default is \fB\-z 6\fP.
This option is actually a shortcut for some predefined settings for quality
and method. If options \fB\-q\fP or \fB\-m\fP are subsequently used, they will
invalidate the effect of this option.
.TP
.BI \-alpha_q " int
Specify the compression factor for alpha compression between 0 and 100.
Lossless compression of alpha is achieved using a value of 100, while the lower
values result in a lossy compression. The default is 100.
.TP
.BI \-preset " string
Specify a set of pre\-defined parameters to suit a particular type of
source material. Possible values are: \fBdefault\fP, \fBphoto\fP,
\fBpicture\fP, \fBdrawing\fP, \fBicon\fP, \fBtext\fP. Since
\fB\-preset\fP overwrites the other parameters' values (except the
\fB\-q\fP one), this option should preferably appear first in the
order of the arguments.
.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 in faster processing time at the expense of
larger file size and lower compression quality.
.TP
.BI \-crop " x_position y_position width height
Crop the source to a rectangle with top\-left corner at coordinates
(\fBx_position\fP, \fBy_position\fP) and size \fBwidth\fP x \fBheight\fP.
This cropping area must be fully contained within the source rectangle.
Note: the cropping is applied \fIbefore\fP any scaling.
.TP
.BI \-resize " width height
Resize the source to a rectangle with size \fBwidth\fP x \fBheight\fP.
If either (but not both) of the \fBwidth\fP or \fBheight\fP parameters is 0,
the value will be calculated preserving the aspect\-ratio. Note: scaling
is applied \fIafter\fP cropping.
.TP
.B \-mt
Use multi\-threading for encoding, if possible.
.TP
.B \-low_memory
Reduce memory usage of lossy encoding by saving four times the compressed
size (typically). This will make the encoding slower and the output slightly
different in size and distortion. This flag is only effective for methods
3 and up, and is off by default. Note that leaving this flag off will have
some side effects on the bitstream: it forces certain bitstream features
like number of partitions (forced to 1). Note that a more detailed report
of bitstream size is printed by \fBcwebp\fP when using this option.
.SS LOSSY OPTIONS
These options are only effective when doing lossy encoding (the default, with
or without alpha).
.TP
.BI \-size " int
Specify a target size (in bytes) to try and reach for the compressed output.
The compressor will make several passes of partial encoding in order to get as
close as possible to this target. If both \fB\-size\fP and \fB\-psnr\fP
are used, \fB\-size\fP value will prevail.
.TP
.BI \-psnr " float
Specify a target PSNR (in dB) to try and reach for the compressed output.
The compressor will make several passes of partial encoding in order to get as
close as possible to this target. If both \fB\-size\fP and \fB\-psnr\fP
are used, \fB\-size\fP value will prevail.
.TP
.BI \-pass " int
Set a maximum number of passes to use during the dichotomy used by
options \fB\-size\fP or \fB\-psnr\fP. Maximum value is 10, default is 1.
If options \fB\-size\fP or \fB\-psnr\fP were used, but \fB\-pass\fP wasn't
specified, a default value of '6' passes will be used.
.TP
.BI \-qrange " int int
Specifies the permissible interval for the quality factor. This is particularly
useful when using multi-pass (\fB\-size\fP or \fB\-psnr\fP options).
Default is 0 100.
If the quality factor is outside this range, it will be clamped.
If the minimum value must be less or equal to the maximum one.
.TP
.B \-af
Turns auto\-filter on. This algorithm will spend additional time optimizing
the filtering strength to reach a well\-balanced quality.
.TP
.B \-jpeg_like
Change the internal parameter mapping to better match the expected size
of JPEG compression. This flag will generally produce an output file of
similar size to its JPEG equivalent (for the same \fB\-q\fP setting), but
with less visual distortion.
.TP
Advanced options:
.TP
.BI \-f " int
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
.BI \-sharpness " int
Specify the sharpness of the filtering (if used).
Range is 0 (sharpest) to 7 (least sharp). Default is 0.
.TP
.B \-strong
Use strong filtering (if filtering is being used thanks to the
\fB\-f\fP option). Strong filtering is on by default.
.TP
.B \-nostrong
Disable strong filtering (if filtering is being used thanks to the
\fB\-f\fP option) and use simple filtering instead.
.TP
.B \-sharp_yuv
Use more accurate and sharper RGB->YUV conversion if needed. Note that this
process is slower than the default 'fast' RGB->YUV conversion.
.TP
.BI \-sns " int
Specify the amplitude of the spatial noise shaping. Spatial noise shaping
(or \fBsns\fP for short) refers to a general collection of built\-in algorithms
used to decide which area of the picture should use relatively less bits,
and where else to better transfer these bits. The possible range goes from
0 (algorithm is off) to 100 (the maximal effect). The default value is 50.
.TP
.BI \-segments " int
Change the number of partitions to use during the segmentation of the
sns algorithm. Segments should be in range 1 to 4. Default value is 4.
This option has no effect for methods 3 and up, unless \fB\-low_memory\fP
is used.
.TP
.BI \-partition_limit " int
Degrade quality by limiting the number of bits used by some macroblocks.
Range is 0 (no degradation, the default) to 100 (full degradation).
Useful values are usually around 30\-70 for moderately large images.
In the VP8 format, the so\-called control partition has a limit of 512k and
is used to store the following information: whether the macroblock is skipped,
which segment it belongs to, whether it is coded as intra 4x4 or intra 16x16
mode, and finally the prediction modes to use for each of the sub\-blocks.
For a very large image, 512k only leaves room to few bits per 16x16 macroblock.
The absolute minimum is 4 bits per macroblock. Skip, segment, and mode
information can use up almost all these 4 bits (although the case is unlikely),
which is problematic for very large images. The partition_limit factor controls
how frequently the most bit\-costly mode (intra 4x4) will be used. This is
useful in case the 512k limit is reached and the following message is displayed:
\fIError code: 6 (PARTITION0_OVERFLOW: Partition #0 is too big to fit 512k)\fP.
If using \fB\-partition_limit\fP is not enough to meet the 512k constraint, one
should use less segments in order to save more header bits per macroblock.
See the \fB\-segments\fP option.
.SS LOGGING OPTIONS
These options control the level of output:
.TP
.B \-v
Print extra information (encoding time in particular).
.TP
.B \-print_psnr
Compute and report average PSNR (Peak\-Signal\-To\-Noise ratio).
.TP
.B \-print_ssim
Compute and report average SSIM (structural similarity
metric, see https://en.wikipedia.org/wiki/SSIM for additional details).
.TP
.B \-print_lsim
Compute and report local similarity metric (sum of lowest error amongst the
collocated pixel neighbors).
.TP
.B \-progress
Report encoding progress in percent.
.TP
.B \-quiet
Do not print anything.
.TP
.B \-short
Only print brief information (output file size and PSNR) for testing purposes.
.TP
.BI \-map " int
Output additional ASCII\-map of encoding information. Possible map values
range from 1 to 6. This is only meant to help debugging.
.SS ADDITIONAL OPTIONS
More advanced options are:
.TP
.BI \-s " width height
Specify that the input file actually consists of raw Y'CbCr samples following
the ITU\-R BT.601 recommendation, in 4:2:0 linear format.
The luma plane has size \fBwidth\fP x \fBheight\fP.
.TP
.BI \-pre " int
Specify some preprocessing steps. Using a value of '2' will trigger
quality\-dependent pseudo\-random dithering during RGBA\->YUVA conversion
(lossy compression only).
.TP
.BI \-alpha_filter " string
Specify the predictive filtering method for the alpha plane. One of 'none',
\&'fast' or 'best', in increasing complexity and slowness order. Default is
\&'fast'. Internally, alpha filtering is performed using four possible
predictions (none, horizontal, vertical, gradient). The 'best' mode will try
each mode in turn and pick the one which gives the smaller size. The 'fast'
mode will just try to form an a priori guess without testing all modes.
.TP
.BI \-alpha_method " int
Specify the algorithm used for alpha compression: 0 or 1. Algorithm 0 denotes
no compression, 1 uses WebP lossless format for compression. The default is 1.
.TP
.B \-exact
Preserve RGB values in transparent area. The default is off, to help
compressibility.
.TP
.BI \-blend_alpha " int
This option blends the alpha channel (if present) with the source using the
background color specified in hexadecimal as 0xrrggbb. The alpha channel is
afterward reset to the opaque value 255.
.TP
.B \-noalpha
Using this option will discard the alpha channel.
.TP
.BI \-hint " string
Specify the hint about input image type. Possible values are:
\fBphoto\fP, \fBpicture\fP or \fBgraph\fP.
.TP
.BI \-metadata " string
A comma separated list of metadata to copy from the input to the output if
present.
Valid values: \fBall\fP, \fBnone\fP, \fBexif\fP, \fBicc\fP, \fBxmp\fP.
The default is \fBnone\fP.
Note: each input format may not support all combinations.
.TP
.B \-noasm
Disable all assembly optimizations.
.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 EXAMPLES
cwebp \-q 50 -lossless picture.png \-o picture_lossless.webp
.br
cwebp \-q 70 picture_with_alpha.png \-o picture_with_alpha.webp
.br
cwebp \-sns 70 \-f 50 \-size 60000 picture.png \-o picture.webp
.br
cwebp \-o picture.webp \-\- \-\-\-picture.png
.SH AUTHORS
\fBcwebp\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 dwebp (1),
.BR gif2webp (1)
.br
Please refer to https://developers.google.com/speed/webp/ for additional
information.

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.\" Hey, EMACS: -*- nroff -*-
.TH DWEBP 1 "November 17, 2021"
.SH NAME
dwebp \- decompress a WebP file to an image file
.SH SYNOPSIS
.B dwebp
.RI [ options ] " input_file.webp
.br
.SH DESCRIPTION
This manual page documents the
.B dwebp
command.
.PP
\fBdwebp\fP decompresses WebP files into PNG, PAM, PPM or PGM images.
Note: Animated WebP files are not supported.
.SH OPTIONS
The basic options are:
.TP
.B \-h
Print usage summary.
.TP
.B \-version
Print the version number (as major.minor.revision) and exit.
.TP
.BI \-o " string
Specify the name of the output file (as PNG format by default).
Using "-" as output name will direct output to 'stdout'.
.TP
.BI \-\- " string
Explicitly specify the input file. This option is useful if the input
file starts with an '\-' for instance. This option must appear \fBlast\fP.
Any other options afterward will be ignored. If the input file is "\-",
the data will be read from \fIstdin\fP instead of a file.
.TP
.B \-bmp
Change the output format to uncompressed BMP.
.TP
.B \-tiff
Change the output format to uncompressed TIFF.
.TP
.B \-pam
Change the output format to PAM (retains alpha).
.TP
.B \-ppm
Change the output format to PPM (discards alpha).
.TP
.B \-pgm
Change the output format to PGM. The output consists of luma/chroma
samples instead of RGB, using the IMC4 layout. This option is mainly
for verification and debugging purposes.
.TP
.B \-yuv
Change the output format to raw YUV. The output consists of
luma/chroma-U/chroma-V samples instead of RGB, saved sequentially as
individual planes. This option is mainly for verification and debugging
purposes.
.TP
.B \-nofancy
Don't use the fancy upscaler for YUV420. This may lead to jaggy
edges (especially the red ones), but should be faster.
.TP
.B \-nofilter
Don't use the in-loop filtering process even if it is required by
the bitstream. This may produce visible blocks on the non-compliant output,
but it will make the decoding faster.
.TP
.BI \-dither " strength
Specify a dithering \fBstrength\fP between 0 and 100. Dithering is a
post-processing effect applied to chroma components in lossy compression.
It helps by smoothing gradients and avoiding banding artifacts.
.TP
.BI \-alpha_dither
If the compressed file contains a transparency plane that was quantized
during compression, this flag will allow dithering the reconstructed plane
in order to generate smoother transparency gradients.
.TP
.B \-nodither
Disable all dithering (default).
.TP
.B \-mt
Use multi-threading for decoding, if possible.
.TP
.BI \-crop " x_position y_position width height
Crop the decoded picture to a rectangle with top-left corner at coordinates
(\fBx_position\fP, \fBy_position\fP) and size \fBwidth\fP x \fBheight\fP.
This cropping area must be fully contained within the source rectangle.
The top-left corner will be snapped to even coordinates if needed.
This option is meant to reduce the memory needed for cropping large images.
Note: the cropping is applied \fIbefore\fP any scaling.
.TP
.B \-flip
Flip decoded image vertically (can be useful for OpenGL textures for instance).
.TP
\fB\-resize\fR, \fB\-scale\fI width height\fR
Rescale the decoded picture to dimension \fBwidth\fP x \fBheight\fP. This
option is mostly intended to reducing the memory needed to decode large images,
when only a small version is needed (thumbnail, preview, etc.). Note: scaling
is applied \fIafter\fP cropping.
If either (but not both) of the \fBwidth\fP or \fBheight\fP parameters is 0,
the value will be calculated preserving the aspect-ratio.
.TP
.B \-quiet
Do not print anything.
.TP
.B \-v
Print extra information (decoding time in particular).
.TP
.B \-noasm
Disable all assembly optimizations.
.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 EXAMPLES
dwebp picture.webp \-o output.png
.br
dwebp picture.webp \-ppm \-o output.ppm
.br
dwebp \-o output.ppm \-\- \-\-\-picture.webp
.br
cat picture.webp | dwebp \-o \- \-\- \- > output.ppm
.SH AUTHORS
\fBdwebp\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 cwebp (1),
.BR gif2webp (1),
.BR webpmux (1)
.br
Please refer to https://developers.google.com/speed/webp/ for additional
information.
.SS Output file format details
PAM: http://netpbm.sourceforge.net/doc/pam.html
.br
PGM: http://netpbm.sourceforge.net/doc/pgm.html
.br
PPM: http://netpbm.sourceforge.net/doc/ppm.html
.br
PNG: http://www.libpng.org/pub/png/png-sitemap.html#info

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.\" Hey, EMACS: -*- nroff -*-
.TH GIF2WEBP 1 "November 17, 2021"
.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.
Using "\-" as output name will direct output to 'stdout'.
.TP
.BI \-\- " string
Explicitly specify the input file. This option is useful if the input
file starts with an '\-' for instance. This option must appear \fBlast\fP.
Any other options afterward will be ignored. If the input file is "\-",
the data will be read from \fIstdin\fP instead of a file.
.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
.B \-mixed
Mixed compression mode: optimize compression of the image by picking either
lossy or lossless compression for each frame heuristically.
.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 \-min_size
Encode image to achieve smallest size. This disables key frame insertion and
picks the dispose method 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
A 'kmax' value of 0 will turn off insertion of key frames. A 'kmax' value of 1
will result in all frames being key frames. 'kmin' value is not taken into
account in both these special cases.
Typical values are in the range 3 to 30. Default values are kmin = 9,
kmax = 17 for lossless compression and kmin = 3, kmax = 5 for lossy compression.
.br
These two options are relevant only for animated images with large number of
frames (>50).
.br
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.
.br
Some restrictions:
.br
(i) kmin < kmax,
.br
(ii) kmin >= kmax / 2 + 1 and
.br
(iii) kmax - kmin <= 30.
.br
If any of these restrictions are not met, they will be enforced automatically.
.TP
.BI \-metadata " string
A comma separated list of metadata to copy from the input to the output if
present.
Valid values: \fBall\fP, \fBnone\fP, \fBicc\fP, \fBxmp\fP.
The default is \fBxmp\fP.
.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 \-mt
Use multi-threading for encoding, if possible.
.TP
.B \-loop_compatibility
If enabled, handle the loop information in a compatible fashion for Chrome
version prior to M62 (inclusive) and Firefox.
.TP
.B \-v
Print extra information.
.TP
.B \-quiet
Do not print anything.
.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 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
.br
gif2webp \-q 70 \-o picture.webp \-\- \-\-\-picture.gif
.br
cat picture.gif | gif2webp \-o \- \-\- \- > output.webp
.SH AUTHORS
\fBgif2webp\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 Urvang Joshi <urvang@google.com>, for the
Debian project (and may be used by others).
.SH SEE ALSO
.BR cwebp (1),
.BR dwebp (1),
.BR webpmux (1)
.br
Please refer to https://developers.google.com/speed/webp/ for additional
information.

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.\" Hey, EMACS: -*- nroff -*-
.TH IMG2WEBP 1 "March 17, 2023"
.SH NAME
img2webp \- create animated WebP file from a sequence of input images.
.SH SYNOPSIS
.B img2webp
[file_options] [[frame_options] frame_file]... [\-o webp_file]
.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 \-near_lossless " int
Specify the level of near\-lossless image preprocessing. This option adjusts
pixel values to help compressibility, but has minimal impact on the visual
quality. It triggers lossless compression mode automatically. The range is 0
(maximum preprocessing) to 100 (no preprocessing, the default). The typical
value is around 60. Note that lossy with \fB\-q 100\fP can at times yield
better results.
.TP
.B \-sharp_yuv
Use more accurate and sharper RGB->YUV conversion if needed. Note that this
process is slower than the default 'fast' RGB->YUV conversion.
.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.

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.\" Hey, EMACS: -*- nroff -*-
.TH VWEBP 1 "November 17, 2021"
.SH NAME
vwebp \- decompress a WebP file and display it in a window
.SH SYNOPSIS
.B vwebp
.RI [ options ] " input_file.webp
.br
.SH DESCRIPTION
This manual page documents the
.B vwebp
command.
.PP
\fBvwebp\fP decompresses a WebP file and displays it in a window using OpenGL.
.SH OPTIONS
.TP
.B \-h
Print usage summary.
.TP
.B \-version
Print version number and exit.
.TP
.B \-noicc
Don't use the ICC profile if present.
.TP
.B \-nofancy
Don't use the fancy YUV420 upscaler.
.TP
.B \-nofilter
Disable in-loop filtering.
.TP
.BI \-dither " strength
Specify a dithering \fBstrength\fP between 0 and 100. Dithering is a
post-processing effect applied to chroma components in lossy compression.
It helps by smoothing gradients and avoiding banding artifacts. Default: 50.
.TP
.BI \-noalphadither
By default, quantized transparency planes are dithered during decompression,
to smooth the gradients. This flag will prevent this dithering.
.TP
.B \-usebgcolor
Fill transparent areas with the bitstream's own background color instead of
checkerboard only. Default is white for non-animated images.
.TP
.B \-mt
Use multi-threading for decoding, if possible.
.TP
.B \-info
Display image information on top of the decoded image.
.TP
.BI \-\- " string
Explicitly specify the input file. This option is useful if the input
file starts with an '\-' for instance. This option must appear \fBlast\fP.
Any other options afterward will be ignored. If the input file is "\-",
the data will be read from \fIstdin\fP instead of a file.
.TP
.SH KEYBOARD SHORTCUTS
.TP
.B 'c'
Toggle use of color profile.
.TP
.B 'b'
Toggle display of background color.
.TP
.B 'i'
Overlay file information.
.TP
.B 'd'
Disable blending and disposal process, for debugging purposes.
.TP
.B 'q' / 'Q' / ESC
Quit.
.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 EXAMPLES
vwebp picture.webp
.br
vwebp picture.webp -mt -dither 0
.br
vwebp \-\- \-\-\-picture.webp
.SH AUTHORS
\fBvwebp\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 for the Debian project (and may be used by others).
.SH SEE ALSO
.BR dwebp (1)
.br
Please refer to https://developers.google.com/speed/webp/ for additional
information.

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.\" Hey, EMACS: -*- nroff -*-
.TH WEBPINFO 1 "November 17, 2021"
.SH NAME
webpinfo \- print out the chunk level structure of WebP files
along with basic integrity checks.
.SH SYNOPSIS
.B webpinfo
.I OPTIONS
.I INPUT
.br
.B webpinfo [\-h|\-help|\-H|\-longhelp]
.br
.SH DESCRIPTION
This manual page documents the
.B webpinfo
command.
.PP
\fBwebpinfo\fP can be used to print out the chunk level structure and bitstream
header information of WebP files. It can also check if the files are of valid
WebP format.
.SH OPTIONS
.TP
.B \-version
Print the version number (as major.minor.revision) and exit.
.TP
.B \-quiet
Do not show chunk parsing information.
.TP
.B \-diag
Show parsing error diagnosis.
.TP
.B \-summary
Show chunk stats summary.
.TP
.BI \-bitstream_info
Parse bitstream header.
.TP
.B \-h, \-help
A short usage summary.
.TP
.B \-H, \-longhelp
Detailed usage instructions.
.SH INPUT
Input files in WebP format. Input files must come last, following
options (if any). There can be multiple input files.
.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 EXAMPLES
.br
webpinfo \-h
.br
webpinfo \-diag \-summary input_file.webp
.br
webpinfo \-bitstream_info input_file_1.webp input_file_2.webp
.br
webpinfo *.webp
.SH AUTHORS
\fBwebpinfo\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 Hui Su <huisu@google.com>,
for the Debian project (and may be used by others).
.SH SEE ALSO
.BR webpmux (1)
.br
Please refer to https://developers.google.com/speed/webp/ for additional
information.

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.\" Hey, EMACS: -*- nroff -*-
.TH WEBPMUX 1 "November 17, 2021"
.SH NAME
webpmux \- create animated WebP files from non\-animated WebP images, extract
frames from animated WebP images, and manage XMP/EXIF metadata and ICC profile.
.SH SYNOPSIS
.B webpmux \-get
.I GET_OPTIONS
.I INPUT
.B \-o
.I OUTPUT
.br
.B webpmux \-set
.I SET_OPTIONS
.I INPUT
.B \-o
.I OUTPUT
.br
.B webpmux \-strip
.I STRIP_OPTIONS
.I INPUT
.B \-o
.I OUTPUT
.br
.B webpmux \-frame
.I FRAME_OPTIONS
.B [ \-frame ... ] [ \-loop
.I LOOP_COUNT
.B ]
.br
.RS 8
.B [ \-bgcolor
.I BACKGROUND_COLOR
.B ] \-o
.I OUTPUT
.RE
.br
.B webpmux \-duration
.I DURATION OPTIONS
.B [ \-duration ... ]
.I INPUT
.B \-o
.I OUTPUT
.br
.B webpmux \-info
.I INPUT
.br
.B webpmux [\-h|\-help]
.br
.B webpmux \-version
.br
.B webpmux argument_file_name
.SH DESCRIPTION
This manual page documents the
.B webpmux
command.
.PP
\fBwebpmux\fP can be used to create/extract from animated WebP files, as well as
to add/extract/strip XMP/EXIF metadata and ICC profile.
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 OPTIONS
.SS GET_OPTIONS (\-get):
.TP
.B icc
Get ICC profile.
.TP
.B exif
Get EXIF metadata.
.TP
.B xmp
Get XMP metadata.
.TP
.BI frame " n
Get nth frame from an animated image. (n = 0 has a special meaning: last frame).
.SS SET_OPTIONS (\-set)
.TP
.BI loop " loop_count
Set loop count on an animated file.
.P
Where: 'loop_count' must be in range [0, 65535].
.TP
.BI bgcolor " A,R,G,B
Set the background color of the canvas on an animated file.
.P
where: 'A', 'R', 'G' and 'B' are integers in the range 0 to 255 specifying the
Alpha, Red, Green and Blue component values respectively.
.TP
.BI icc " file.icc
Set ICC profile.
.P
Where: 'file.icc' contains the ICC profile to be set.
.TP
.BI exif " file.exif
Set EXIF metadata.
.P
Where: 'file.exif' contains the EXIF metadata to be set.
.TP
.BI xmp " file.xmp
Set XMP metadata.
.P
Where: 'file.xmp' contains the XMP metadata to be set.
.SS STRIP_OPTIONS (\-strip)
.TP
.B icc
Strip ICC profile.
.TP
.B exif
Strip EXIF metadata.
.TP
.B xmp
Strip XMP metadata.
.SS DURATION_OPTIONS (\-duration)
Amend the duration of a specific interval of frames. This option is only
effective on animated WebP and has no effect on a single-frame file.
.TP
.I duration[,start[,end]]
Where:
.br
.B duration
is the duration for the interval in milliseconds (mandatory).
Must be non-negative.
.br
.B start
is the starting frame index of the interval (optional).
.br
.B end
is the ending frame index (inclusive) of the interval (optional).
.TP
The three typical usages of this option are:
.br
.B -duration d
set the duration to 'd' for the whole animation.
.br
.B -duration d,f
set the duration of frame 'f' to 'd'.
.br
.B -duration d,start,end
set the duration to 'd' for the whole [start,end] interval.
.TP
.P
Note that the frames outside of the [start, end] interval will remain untouched.
The 'end' value '0' has the special meaning 'last frame of the animation'.
.TP
.I Reminder:
frame indexing starts at '1'.
.br
.SS FRAME_OPTIONS (\-frame)
Create an animated WebP file from multiple (non\-animated) WebP images.
.TP
.I file_i +di[+xi+yi[+mi[bi]]]
Where: 'file_i' is the i'th frame (WebP format), 'xi','yi' specify the image
offset for this frame, 'di' is the pause duration before next frame, 'mi' is
the dispose method for this frame (0 for NONE or 1 for BACKGROUND) and 'bi' is
the blending method for this frame (+b for BLEND or \-b for NO_BLEND).
Argument 'bi' can be omitted and will default to +b (BLEND).
Also, 'mi' can be omitted if 'bi' is omitted and will default to 0 (NONE).
Finally, if 'mi' and 'bi' are omitted then 'xi' and 'yi' can be omitted and will
default to +0+0.
.TP
.BI \-loop " n
Loop the frames n number of times. 0 indicates the frames should loop forever.
Valid range is 0 to 65535 [Default: 0 (infinite)].
.TP
.BI \-bgcolor " A,R,G,B
Background color of the canvas.
.br
where: 'A', 'R', 'G' and 'B' are integers in the range 0 to 255 specifying the
Alpha, Red, Green and Blue component values respectively
[Default: 255,255,255,255].
.SS INPUT
.TP
Input file in WebP format.
.SS OUTPUT (\-o)
.TP
Output file in WebP format.
.SS Note:
.TP
The nature of EXIF, XMP and ICC data is not checked and is assumed to be valid.
.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 EXAMPLES
.P
Add ICC profile:
.br
webpmux \-set icc image_profile.icc in.webp \-o icc_container.webp
.P
Extract ICC profile:
.br
webpmux \-get icc icc_container.webp \-o image_profile.icc
.P
Strip ICC profile:
.br
webpmux \-strip icc icc_container.webp \-o without_icc.webp
.P
Add XMP metadata:
.br
webpmux \-set xmp image_metadata.xmp in.webp \-o xmp_container.webp
.P
Extract XMP metadata:
.br
webpmux \-get xmp xmp_container.webp \-o image_metadata.xmp
.P
Strip XMP metadata:
.br
webpmux \-strip xmp xmp_container.webp \-o without_xmp.webp
.P
Add EXIF metadata:
.br
webpmux \-set exif image_metadata.exif in.webp \-o exif_container.webp
.P
Extract EXIF metadata:
.br
webpmux \-get exif exif_container.webp \-o image_metadata.exif
.P
Strip EXIF metadata:
.br
webpmux \-strip exif exif_container.webp \-o without_exif.webp
.P
Create an animated WebP file from 3 (non\-animated) WebP images:
.br
webpmux \-frame 1.webp +100 \-frame 2.webp +100+50+50
.br
.RS 8
\-frame 3.webp +100+50+50+1+b \-loop 10 \-bgcolor 255,255,255,255
.br
\-o anim_container.webp
.RE
.P
Get the 2nd frame from an animated WebP file:
.br
webpmux \-get frame 2 anim_container.webp \-o frame_2.webp
.P
Using \-get/\-set/\-strip with input file name starting with '\-':
.br
webpmux \-set icc image_profile.icc \-o icc_container.webp \-\- \-\-\-in.webp
.br
webpmux \-get icc \-o image_profile.icc \-\- \-\-\-icc_container.webp
.br
webpmux \-strip icc \-o without_icc.webp \-\- \-\-\-icc_container.webp
.SH AUTHORS
\fBwebpmux\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 Vikas Arora <vikaas.arora@gmail.com>,
for the Debian project (and may be used by others).
.SH SEE ALSO
.BR cwebp (1),
.BR dwebp (1),
.BR gif2webp (1)
.br
Please refer to https://developers.google.com/speed/webp/ for additional
information.