WebP Still Image Format

WebP Still Image Format was released by Google in September 2010. WebP is based on VP8 intra coding. WebP supports both lossless and lossy compression. It is reported to offer 39.8% more byte-size efficiency than JPEG for the same quality. 

For more results of WebP comparison with other still image codecs (JPEG, JPEG2000, JPEG XR) the author recommend the paper “Objective assessment of the WebP image coding algorithm”, Giaime Ginesu et al., 2012.

WebP project document

Binaries for WebP encoder and decoder are located at https://storage.googleapis.com/downloads.webmproject.org/releases/webp/index.html?utm_source=developers.google.com&utm_medium=referral

i take libwebp-1.2.4-windows-x64.zip , upon extracting pre-compiled exe-files are located in ‘bin’ folder

 

Encoding Raw Image with cwebp.exe

Use case: Lossless encoding from png to webp

 cwebp.exe -lossless -exact   test.png -o test.webp

 

Use case: Encoding 1568×1080 yuv420p image with a predefined psnr quality (in the following case psnr = 40dB)

cwebp.exe -s 1568 1080 -psnr 40  crowd_1568x1080.yuv -o crowd_1568x1080.webp

 

Decoding 

Decoded image in the format bmp:

dwebp.exe crowd_1568x1080.webp -bmp -o crowd_1568x1080.bmp

Decoded image in the format yuv420p:

dwebp.exe crowd_1568x1080.webp -yuv    -o   crowd_1568x1080_dec.yuv

verification with ‘ffplay’:

    ffplay -s 1568×1080     crowd_1568x1080_dec.yuv