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.	Note:
       Animated WebP files are not supported.

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
	      appear 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
	      sequentially as individual planes. This option is mainly for
	      verification 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
	      banding 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
	      coordinates 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
	      decode large images, when only a small version is needed
	      (thumbnail, 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.


EXIT STATUS
       If there were no problems during execution, dwebp exits with the value
       of the C constant EXIT_SUCCESS. This is usually zero.

       If an error occurs, dwebp exits with the value of the C constant
       EXIT_FAILURE. This is usually one.


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.googlesource.com/webm/libwebp

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


REPORTING BUGS
       Please report all bugs to the issue tracker:
       https://issues.webmproject.org
       Patches welcome! See this page to get started:
       https://www.webmproject.org/code/contribute/submitting-patches/


SEE ALSO
       cwebp(1), gif2webp(1), webpmux(1)
       Please refer to https://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

				 July 18, 2024			      DWEBP(1)