bbe32df1e3
new options: dwebp -alpha_dither vwebp -noalphadither When the source was marked as quantized, we use a threshold-averaging filter to smooth the decoded alpha plane. Note: this option forces the decoding of alpha data in one pass, and might slow the decoding a bit. The new field in WebPDecoderOptions struct is 'alpha_dithering_strength' (0 by default, means: off). Max strength value is '100'. Change-Id: I218e21af96360d4781587fede95f8ea4e2b7287a
91 lines
2.2 KiB
Groff
91 lines
2.2 KiB
Groff
.\" Hey, EMACS: -*- nroff -*-
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.TH VWEBP 1 "June 13, 2014"
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.SH NAME
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vwebp \- decompress a WebP file and display it in a window
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.SH SYNOPSIS
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.B vwebp
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.RI [ options ] " input_file.webp
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.br
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.SH DESCRIPTION
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This manual page documents the
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.B vwebp
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command.
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.PP
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\fBvwebp\fP decompresses a WebP file and displays it in a window using OpenGL.
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.SH OPTIONS
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.TP
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.B \-h
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Print usage summary.
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.TP
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.B \-version
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Print version number and exit.
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.TP
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.B \-noicc
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Don't use the ICC profile if present.
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.TP
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.B \-nofancy
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Don't use the fancy YUV420 upscaler.
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.TP
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.B \-nofilter
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Disable in-loop filtering.
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.TP
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.BI \-dither " strength
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Specify a dithering \fBstrength\fP between 0 and 100. Dithering is a
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post-processing effect applied to chroma components in lossy compression.
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It helps by smoothing gradients and avoiding banding artifacts. Default: 50.
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.TP
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.BI \-noalphadither
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By default, quantized transparency planes are dithered during decompression,
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to smooth the gradients. This flag will prevent this dithering.
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.TP
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.B \-mt
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Use multi-threading for decoding, if possible.
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.TP
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.B \-info
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Display image information on top of the decoded image.
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.TP
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.BI \-\- " string
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Explicitly specify the input file. This option is useful if the input
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file starts with an '\-' for instance. This option must appear \fBlast\fP.
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Any other options afterward will be ignored. If the input file is "\-",
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the data will be read from \fIstdin\fP instead of a file.
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.TP
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.SH KEYBOARD SHORTCUTS
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.TP
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.B 'c'
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Toggle use of color profile.
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.TP
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.B 'i'
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Overlay file information.
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.TP
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.B 'q' / 'Q' / ESC
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Quit.
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.SH BUGS
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Please report all bugs to our issue tracker:
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http://code.google.com/p/webp/issues
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.br
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Patches welcome! See this page to get started:
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http://www.webmproject.org/code/contribute/submitting-patches/
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.SH EXAMPLES
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vwebp picture.webp
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.br
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vwebp picture.webp -mt -dither 0
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.br
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vwebp \-\- \-\-\-picture.webp
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.SH AUTHORS
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\fBvwebp\fP was written by the WebP team.
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.br
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The latest source tree is available at http://www.webmproject.org/code
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.PP
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This manual page was written for the Debian project (and may be used by others).
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.SH SEE ALSO
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.BR dwebp (1)
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.br
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Please refer to http://developers.google.com/speed/webp/ for additional
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information.
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