| 摘要 |
The invention provides a method of and a device for coding ( 10* ) an image sequence (g(i,j,k)). The device ( 10* ) has a noise filter ( 12 ) for noise filtering ( 12 ) the image sequence (g(i,j,k)), and for regarding the noise filtering ( 12 ) as a rate-distortion optimization problem in order to adapt the response of the noise filter ( 12 ). In particular, a filter parameter set (C) is determined to adapt the response of the filter ( 12 ) in that the image sequence (g(i,j,k)) is encoded using an optimal bit-budget, which is the bit-budget used for compressing a noise-free image sequence, and the distortion for the given bit-budget is minimized. A solution of the rate-distortion problem is proposed that calculates ( 12 ) the filter parameter set (C) by a Lagrange multiplier method. Separate minimization is used to determine each parameter of the parameter set (C) independently. In a practical embodiment, a spatial adaptive weighted averaging (SAWA) filtering ( 23 ) is used to estimate the bit budget (R<SUP>f*</SUP>) and to pre-filter the image sequence (g(i,j,k)). |
