| 摘要 |
The invention relates to an encoding method for the compression of a video sequence by means of a three-dimensional wavelet transform. This method is based on a hierarchical subband encoding process leading to transform coefficients that constitute a hierarchical pyramid. A spatio-temporal orientation tree, in which the roots are formed with the pixels of the approximation subband and the offspring of each of these pixels is formed with the pixels of the higher subbands, defines the spatio-temporal relationship inside said pyramid. The initial subband structure of the wavelet transform is, in the encoding process, preserved by scanning the subbands one after the other in an order that respects the parent-off-spring dependencies formed in the tree, and flags "off/on " are added to each coefficient of the tree in view of a progressive transmission of the most significant bits of the coefficients. According to the invention, an additional, specific one bit flag is added to each subband for giving an information about the overall state of its coefficients, said additional information about the parent-offspring dependencies of each subband being then used to either process said subband if said flag has a first one of its two possible values or skip it if said flag has the second one said two possible values. |
