Patent ID: 9258568
Filing Date: 2016-02-09
CPC Classification: H04N

Claim Text:
1. A quantization method performed by an encoder to generate encoded data of an image to be transmitted to a decoder for decoding, comprising: acquiring a coefficient matrix to be used in performing quantization on the image to generate encoded data of the image, the coefficient matrix having a plurality of coefficients, and the coefficients of the coefficient matrix being divided into a plurality of frequency bands, wherein a number of the frequency bands is smaller than a number of coefficients in the coefficient matrix; assigning one weighting value to each frequency band in the coefficient matrix such that every coefficient in said each frequency band has the same weighting value that is assigned to said each frequency band; generating a parameter set having multiple band parameters, each band parameter corresponding to a frequency band of the coefficient matrix and being derived from the weighting value of the corresponding frequency band, such that a number of the band parameters is smaller than the number of the coefficients in the coefficient matrix; and writing the parameter set having the band parameters together with the encoded data of the image into a bitstream to be transmitted to the decoder.