System and method for enhancing videos from drift-free scalable bitstream

A parameter estimation and optimal reconstruction (PEOR) method for use in a scalable decoder, the method comprising:

• determining the set of quantization occurrences;
• estimating a parameter a, wherein a is estimated according to the equation
• 31 α ^ l = - log ⁡ ( 1 - P ^ l ) b l ,
• wherein bl denotes each of a set of quantizer decision levels l, and {circumflex over (P)}l is the sum of a set of a normalized frequency of occurrences of data quantized to each quantizer decision level 1,2, . . . ,l;
• generating a preliminary reconstruction point according to the equation
• 32 x ~ i , n e = a i , n + d i , n ⁡ ( ρ ;
• x ~ i , n - 1 e ) ;
• and
• smoothing the preliminary reconstruction point to generate an optimal reconstruction point.

A parameter estimation and optimal reconstruction (PEOR) system for use in a scalable decoder, comprising:

• a reconstruction system for determining an optimal reconstruction according to the equation:
• 36 x ~ i , n e = a i , n + E z ⁢ { d i , n ⁡ ( ρ ;
• x ~ i , n - 1 e + Z ) } ,
• wherein Z is a quantization noise, Ez is an expectation with respect to quantization noise Z,
• 37 d i , n ⁡ ( ρ ;
• x ~ i , n - 1 e + Z )
• denotes a reconstruction offset,
• 38 x ~ i , n - 1 e
• is an expectation of a discrete cosine transform (DCT) coefficient of a previous frame, ρ equals a predetermined value between −1 and 1, and ai,n is a beginning of a quantization interval.