LZ77 and
LZ78 are the two
lossless data compression algorithms published in papers by
Abraham Lempel and
Jacob Ziv in 1977 and 1978. They are also known as
LZ1 and
LZ2 respectively. These two algorithms form the basis for many variations including
LZW,
LZSS,
LZMA and others. Besides their academic influence, these algorithms formed the basis of several ubiquitous compression schemes, including
GIF and the
DEFLATE algorithm used in
PNG.