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, 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).

-ppm

Change the output format to PPM.

-pgm

Change the output format to PGM. The output consist of luma/chroma samples instead of RGB, using the ICM4 layout. This option is mainly for verification and debugging purpose.

-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.

 

Examples:¶

dwebp picture.webp -o output.png dwebp picture.webp -ppm -o output.ppm

SEE ALSO¶

cwebp(1). Please refer to http://code.google.com/speed/webp/ for additional information.

AUTHOR¶

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).