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).
-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 ICM4 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-compli-
ant output, but will make the decoding faster.
-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 scal-
ing.
-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.
-v Print extra information (decoding time in particular).
-noasm Disable all assembly optimizations.
BUGS
Please report all bugs to our issue tracker: http://code.google.com/p/webp/issues
Patches welcome! See this page to get started: http://www.webmproject.org/code/contribute/submitting-patches/
EXAMPLES
dwebp picture.webp -o output.png
dwebp picture.webp -ppm -o output.ppm
AUTHORS
dwebp was written by the WebP team.
The latest source tree is available at http://www.webmproject.org/code
This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>, for the Debian project (and may be used by others).
SEE ALSO
cwebp(1), webpmux(1), gif2webp(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
February 01, 2013 DWEBP(1)