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-compliant 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 scaling.
-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).