BPG (Better Portable Graphics) is a new image format.  Its purpose is
to replace the JPEG image format when quality or file size is an
issue.  Its main advantages are:

+ High compression ratio.  Files are much smaller than JPEG for
similar quality.

+ Supported by most Web browsers with a small Javascript decoder
(gzipped size:  71 KB).

+ Based on a subset of the HEVC open video compression standard.

+ Supports the same chroma formats as JPEG (grayscale, YCbCr 4:2:0,
4:2:2, 4:4:4) to reduce the losses during the conversion.  An alpha
channel is supported.  The RGB, YCgCo and CMYK color spaces are also
supported.

+ Native support of 8 to 14 bits per channel for a higher dynamic
range.

+ Lossless compression is supported.

+ Various metadata (such as EXIF, ICC profile, XMP) can be included.

Homepage:
https://bellard.org/bpg/
