US 12,149,265 B2
Efficient update of cumulative distribution functions for image compression
Pascal Massimino, Orsay (FR); and Vincent Rabaud, Paris (FR)
Assigned to GOOGLE LLC, Mountain View, CA (US)
Appl. No. 17/904,030
Filed by GOOGLE LLC, Mountain View, CA (US)
PCT Filed Jul. 6, 2020, PCT No. PCT/US2020/070236
§ 371(c)(1), (2) Date Aug. 11, 2022,
PCT Pub. No. WO2022/010531, PCT Pub. Date Jan. 13, 2022.
Prior Publication US 2023/0085142 A1, Mar. 16, 2023
Int. Cl. H03M 7/30 (2006.01); H03M 7/40 (2006.01); H04N 19/91 (2014.01)
CPC H03M 7/3071 (2013.01) [H03M 7/4006 (2013.01); H04N 19/91 (2014.11)] 21 Claims
OG exemplary drawing
 
1. A method, comprising:
receiving raw data for encoding, the raw data represented by an alphabet of symbols;
initializing a cumulative distribution function (CDF) array representing a CDF evaluated at a plurality of indices, each of the plurality of indices representing a symbol of the alphabet, wherein the symbol represents a portion of the raw data, the CDF at an index of the plurality of indices representing a cumulative sum of probabilities of symbols of the alphabet represented by indices of the plurality of indices less than or equal to the index;
in response to receiving a first symbol of the alphabet representing a first portion of the raw data, updating the CDF array based on a first mixing CDF array and a second mixing CDF array to produce an updated CDF array, the first mixing CDF array having values that are independent of the first symbol, the second mixing CDF array having values based on the first symbol, the updated CDF array being used to determine a probability of a second symbol of the alphabet representing a second portion of the raw data; and
encoding the first symbol and the second symbol using the updated CDF array to produce a codeword, the codeword, when decoded, indicating the first portion and the second portion of the raw data.