The Marilyn Manson Wiki:Images support

WebP support

Unfortunately the current instance of the wiki does not support the WebP format, neither lossless nor lossy. In order to overcome this limitation, as of now unless the WebP format support is done, it is strongly recommended to convert the images to the loseless PNG format that may be less efficient from the image encoding perspective and may result in files with larger size.

Also to indicate that converted images were WebP files initially, it is also recommended adding the .png extension to the newly converted image file. For example, foobar.webp should become foobar.webp.png once converted.

Batch conversion from WebP to PNG

On Unix-like OSes/machines batch processing is the easiest using the ImageMagick toolset.

For example, let's first make sure all the given files in the current directory are really WebP files,

 $ file *.webp
 6egvkfouamqd1.webp: RIFF (little-endian) data, Web/P image, VP8 encoding, 960x960, Scaling: [none]x[none], YUV color, decoders should clamp
 ott8wdiuamqd1.webp: RIFF (little-endian) data, Web/P image, VP8 encoding, 960x960, Scaling: [none]x[none], YUV color, decoders should clamp
 r8pyqbluamqd1.webp: RIFF (little-endian) data, Web/P image, VP8 encoding, 960x960, Scaling: [none]x[none], YUV color, decoders should clamp

All of the example files are .webp files that are truly RIFF-encoded files the WebP uses to encode image files in.

The above files batch conversion example:

 $ for FILE in *.webp; do convert -verbose "$FILE" "$FILE.png"; done
 6egvkfouamqd1.webp WEBP 960x960 960x960+0+0 8-bit sRGB 89286B 0.010u 0:00.014
 6egvkfouamqd1.webp=>6egvkfouamqd1.webp.png WEBP 960x960 960x960+0+0 8-bit sRGB 942925B 0.200u 0:00.187
 ott8wdiuamqd1.webp WEBP 960x960 960x960+0+0 8-bit sRGB 63716B 0.000u 0:00.009
 ott8wdiuamqd1.webp=>ott8wdiuamqd1.webp.png WEBP 960x960 960x960+0+0 8-bit sRGB 636725B 0.120u 0:00.116
 r8pyqbluamqd1.webp WEBP 960x960 960x960+0+0 8-bit sRGB 147152B 0.010u 0:00.013
 r8pyqbluamqd1.webp=>r8pyqbluamqd1.webp.png WEBP 960x960 960x960+0+0 8-bit sRGB 1.16213MiB 0.170u 0:00.172

Now the WebP files have their PNG format equivalents to be uploaded to the wiki.