Abstract: The invention relates to a method for compressing a set of input binary data values x, all coded in a same number B of bits, into a corresponding set of output data values x?, all coded in a smaller number b of bits, obtainable by (i) computing a quantization step size dq dq = 2 B + 1 2 b + 1 - 1 (ii) dividing the range of values [0, 2B?1[, into 2b subranges, the first subrange being [0, INT(dq/2)[ the ith subrange being [INT((i?3/2)*dq)+1, INT((i?1/2)*dq)[, for i going from 2 to 2b The invention also relates to a method for decompressing data and to applications of said method for compressing/decompressing video data, and to devices for performing these operations.

Abstract: The invention provides a method and device for compressing a sequence of signed coefficients wherein coefficients are grouped, for each group, the greatest coded line index (GCLI) is determined, a quantization level t is applied and only the GCLI-t lowest weight bits of the coefficients are copied into the output stream together with the value of the GCLI. According to the invention, sign bits are not coded for coefficient having a zero quantized value. The invention also provides a method for determining a data budget required for compressing a sequence of signed coefficients, in dependence of a quantization level, and a method for compressing an image within the limits of a given data budget constraint. The invention provides a compressed data set coding an image in an efficient way.

Abstract: The invention provides a method and device for compressing a sequence of signed coefficients wherein coefficients are grouped, for each group, the greatest coded line index (GCLI) is determined, a quantization level t is applied and only the GCLI-t lowest weight bits of the coefficients are copied into the output stream together with the value of the GCLI. According to the invention, sign bits are not coded for coefficient having a zero quantized value. The invention also provides a method for determining a data budget required for compressing a sequence of signed coefficients, in dependence of a quantization level, and a method for compressing an image within the limits of a given data budget constraint. The invention provides a compressed data set coding an image in an efficient way.

Abstract: The invention relates to a method for compressing a set of input binary data values x, all coded in a same number B of bits, into a corresponding set of output data values x?, all coded in a smaller number b of bits, obtainable by (i) computing a quantization step size dq dq = 2 B + 1 2 b + 1 - 1 (ii) dividing the range of values [0, 2B?1[, into 2b subranges, the first subrange being [0, INT(dq/2)[ the ith subrange being [INT((i?3/2)*dq)+1, INT((i?1/2)*dq)[, for i going from 2 to 2b The invention also relates to a method for decompressing data and to applications of said method for compressing/decompressing video data, and to devices for performing these operations.