VP8L

• Company: Google
• Specification: https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification
• Sample implementation: https://code.google.com/p/webm/source/browse/src/dec/vp8l.c?repo=libwebp&r=2fc130157767e529fedd42fad0c70c13804058ab

From Google's WebP page: "Lossless WebP compression uses already seen image fragments in order to exactly reconstruct new pixels. It can also use a local palette if no interesting match is found. This palette is continuously updated to re-use recent colors. This compression mode is named "VP8L" and shares some common features with the so-called LZ77 compression algorithm."