LOCO-I (ISO/IEC 14495-1)
for i = 1,2,3 and
where β is the number of bits/pixel. This produces a projection of the residues from the dynamic range [−α + 1,α− 1] to [−α∕2,α∕2 − 1], where α = 2β is the size of the source alphabet.
After that, the residues are in the range [0,1,,2β − 1]
LOCO-I uses a Rice encoder that can be very redundant if the probability distributions are very narrow. To overcome this drawback, there is a special encoding mode for this situation that is triggered when a = b = c = d.
The normal mode is re-started when if s≠a or the end of a line has been reached.