We introduce COOL-CHIC, a Coordinate-based Low Complexity Hierarchical Image
Codec. It is a learned alternative to autoencoders with approximately 2000
parameters and 2500 multiplications per decoded pixel. Despite its low
complexity, COOL-CHIC offers compression performance close to modern
conventional MPEG codecs such as HEVC and VVC. This method is inspired by the
Coordinate-based Neural Representation, where an image is represented as a
learned function which maps pixel coordinates to RGB values. The parameters of
the mapping function are then sent using entropy coding. At the receiver side,
the compressed image is obtained by evaluating the mapping function for all
pixel coordinates. COOL-CHIC implementation is made available upon request