| .\" Hey, EMACS: -*- nroff -*- |
| .TH DWEBP 1 "January 24, 2012" |
| .SH NAME |
| dwebp \- decompress a WebP file to an image file |
| .SH SYNOPSIS |
| .B dwebp |
| .RI [ options ] " input_file.webp |
| .br |
| .SH DESCRIPTION |
| This manual page documents the |
| .B dwebp |
| command. |
| .PP |
| \fBdwebp\fP decompresses WebP files into PNG, PPM or PGM images. |
| .SH OPTIONS |
| The basic options are: |
| .TP |
| .B \-h |
| Print usage summary. |
| .TP |
| .B \-version |
| Print the version number (as major.minor.revision) and exit. |
| .TP |
| .B \-o string |
| Specify the name of the output file (as PNG format by default). |
| .TP |
| .B \-ppm |
| Change the output format to PPM. |
| .TP |
| .B \-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. |
| .TP |
| .B \-nofancy |
| Don't use the fancy upscaler for YUV420. This may lead to jaggy |
| edges (especially the red ones), but should be faster. |
| .TP |
| .B \-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. |
| .TP |
| .B \-mt |
| Use multi-threading for decoding, if possible. |
| .TP |
| .B \-crop x_position y_position width height |
| Crop the decoded picture to a rectangle with top-left corner at coordinates |
| (\fBx_position\fP, \fBy_position\fP) and size \fBwidth\fP x \fBheight\fP. |
| 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 \fIbefore\fP any scaling. |
| .TP |
| .B \-scale width height |
| Rescale the decoded picture to dimension \fBwidth\fP x \fBheight\fP. 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 \fIafter\fP cropping. |
| .TP |
| .B \-v |
| Print extra information (decoding time in particular). |
| .TP |
| .B \-noasm |
| Disable all assembly optimizations. |
| |
| .SH BUGS |
| Please report all bugs to our issue tracker: |
| http://code.google.com/p/webp/issues |
| .br |
| Patches welcome! See this page to get started: |
| http://www.webmproject.org/code/contribute/submitting-patches/ |
| |
| .SH EXAMPLES |
| dwebp picture.webp \-o output.png |
| .br |
| dwebp picture.webp \-ppm \-o output.ppm |
| |
| .SH AUTHORS |
| \fBdwebp\fP was written by the WebP team. |
| .br |
| The latest source tree is available at http://www.webmproject.org/code |
| .PP |
| This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>, |
| for the Debian project (and may be used by others). |
| |
| .SH SEE ALSO |
| .BR cwebp (1). |
| .br |
| Please refer to http://developers.google.com/speed/webp/ for additional |
| information. |
