Elias delta code is a universal code encoding the positive integers. To code a number: In data compression, a universal code maps the integers (representing messages) onto self-delimiting binary codewords. ...

1. Write it in binary.
2. Count the bits, remove the leading one, and write that number in binary preceding the previous bit string.
3. Subtract 1 from the number of bits written in step 2 and prepend that many zeros.

An equivalent way to express the same process:

1. Separate the integer into the highest power of 2 it contains (2^N) and the remaining N binary digits of the integer.
2. Encode N with Elias gamma coding.
3. Append the remaining N binary digits to this representation of N.

The code begins: Elias gamma code is a universal code encoding the positive integers. ...

 1 1 2 0100 3 0101 4 01100 5 01101 6 01110 7 01111 8 00100000 9 00100001 10 00100010 11 00100011 12 00100100 13 00100101 14 00100110 15 00100111 16 001010000 17 001010001 

To decode an Elias delta-coded integer:

1. Read and count zeroes from the stream until you reach the first one. Call this count of zeroes L.
2. Considering the one that was reached to be the first digit of an integer, with a value of 2^L, read the remaining L digits of the integer. Call this integer M.
3. Put a one in the first place of our final output, representing the value 2^M. Read and append the following M digits.

See also: Elias gamma coding, Elias omega coding Elias gamma code is a universal code encoding the positive integers. ... Elias omega coding is a universal code encoding the positive integers. ...