Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
DWEBP(1)		    General Commands Manual		      DWEBP(1)

NAME
       dwebp - decompress a WebP file to an image file

SYNOPSIS
       dwebp [options] input_file.webp

DESCRIPTION
       This manual page	documents the dwebp command.

       dwebp decompresses WebP files into PNG, PAM, PPM	or PGM images.

OPTIONS
       The basic options are:

       -h     Print usage summary.

       -version
	      Print the	version	number (as major.minor.revision) and exit.

       -o string
	      Specify  the name	of the output file (as PNG format by default).
	      Using "-"	as output name will direct output to 'stdout'.

       -- string
	      Explicitly specify the input file. This option is	useful if  the
	      input file starts	with an	'-' for	instance. This option must ap-
	      pear last.  Any other options afterward will be ignored. If  the
	      input file is "-", the data will be read from stdin instead of a
	      file.

       -bmp   Change the output	format to uncompressed BMP.

       -tiff  Change the output	format to uncompressed TIFF.

       -pam   Change the output	format to PAM (retains alpha).

       -ppm   Change the output	format to PPM (discards	alpha).

       -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.

       -yuv   Change the output	format to raw  YUV.  The  output  consists  of
	      luma/chroma-U/chroma-V  samples  instead	of  RGB, saved sequen-
	      tially as	individual planes. This	option is mainly for verifica-
	      tion and debugging purposes.

       -nofancy
	      Don't  use the fancy upscaler for	YUV420.	This may lead to jaggy
	      edges (especially	the red	ones), but should be faster.

       -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.

       -dither strength
	      Specify a	dithering strength between 0 and 100. Dithering	 is  a
	      post-processing  effect  applied	to  chroma components in lossy
	      compression.  It helps by	smoothing gradients and	avoiding band-
	      ing artifacts.

       -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.

       -nodither
	      Disable all dithering (default).

       -mt    Use multi-threading for decoding,	if possible.

       -crop x_position	y_position width height
	      Crop the decoded picture to a rectangle with top-left corner  at
	      coordinates  (x_position,	 y_position)  and size width x height.
	      This cropping area must be fully	contained  within  the	source
	      rectangle.   The top-left	corner will be snapped to even coordi-
	      nates if needed.	This option is	meant  to  reduce  the	memory
	      needed for cropping large	images.	 Note: the cropping is applied
	      before any scaling.

       -flip  Flip decoded image vertically (can be useful for OpenGL textures
	      for instance).

       -resize,	-scale width height
	      Rescale  the  decoded  picture to	dimension width	x height. This
	      option is	mostly intended	to reducing the	memory needed  to  de-
	      code  large  images, when	only a small version is	needed (thumb-
	      nail, preview, etc.). Note: scaling is applied  after  cropping.
	      If either	(but not both) of the width or height parameters is 0,
	      the value	will be	calculated preserving the aspect-ratio.

       -quiet Do not print anything.

       -v     Print extra information (decoding	time in	particular).

       -noasm Disable all assembly optimizations.

BUGS
       Please	 report	    all	    bugs     to	    the	    issue     tracker:
       https://bugs.chromium.org/p/webp
       Patches	welcome!  See  this  page  to get started: http://www.webmpro-
       ject.org/code/contribute/submitting-patches/

EXAMPLES
       dwebp picture.webp -o output.png
       dwebp picture.webp -ppm -o output.ppm
       dwebp -o	output.ppm -- ---picture.webp
       cat picture.webp	| dwebp	-o - --	- > output.ppm

AUTHORS
       dwebp is	a part of libwebp and was written by the WebP team.
       The  latest  source  tree  is  available	 at   https://chromium.google-
       source.com/webm/libwebp

       This   manual   page  was  written  by  Pascal  Massimino  <pascal.mas-
       simino@gmail.com>, for the Debian project (and may be used by others).

SEE ALSO
       cwebp(1), gif2webp(1), webpmux(1)
       Please refer to http://developers.google.com/speed/webp/	for additional
       information.

   Output file format details
       PAM: http://netpbm.sourceforge.net/doc/pam.html
       PGM: http://netpbm.sourceforge.net/doc/pgm.html
       PPM: http://netpbm.sourceforge.net/doc/ppm.html
       PNG: http://www.libpng.org/pub/png/png-sitemap.html#info

				 June 23, 2016			      DWEBP(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | BUGS | EXAMPLES | AUTHORS | SEE ALSO

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=dwebp&sektion=1&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help