Real WEBP (or RWP) is a new image file format made to be a competitor to Google’s WEBP.

It stores images by encoding the color of each pixel as an HTML/CSS color name. An example RWP file goes as follows:

RWP 4 3
red orange yellow green
cyan blue magenta red
white grey dimgrey black

Which becomes this: and when resized becomes this:

How does it do an a regular image?#

Here’s the original: It’s a 22 MB, 6000 x 4000 JPEG

Without dithering#

When converted into RWP (without dithering) it makes a 224 MB file. If you want to download it I have a gzipped version here that’s only 8.8 MB

Just for fun, here’s a small part from the beginning of the file

RWP 6000 4000
PowderBlue PaleTurquoise PowderBlue LightBlue PowderBlue PowderBlue PaleTurquoise LightBlue LightBlue LightBlue PaleTurquoise LightBlue LightBlue LightBlue LightBlue LightBlue PowderBlue LightBlue LightBlue LightBlue LightBlue PowderBlue PowderBlue PaleTurquoise LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue PaleTurquoise PowderBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue PowderBlue LightBlue LightBlue LightBlue LightBlue LightBlue PowderBlue PowderBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue LightBlue

There are 4000 lines, each of them with 6000 color names

When converted back into a PNG it makes this 9.8 MB file:

With dithering#

When dithering is on, the RWP file is 229 MB. The gzip is here and it’s 15 MB.

When converted back into a PNG it makes this:

GitHub: CalSch/real-webp