d*******n
发帖数: 369 | 1 我知道他是context adaptive的。有一下两个方面：
1. The number of non-zero coefficients in neighbouring blocks is correlated.
The number of coefficients is encoded using a look-up table; the choice of
look-up table depends on the number of non-zero coefficients in neighbouring
blocks.
2. The level (magnitude) of non-zero coefficients tends to be higher at the
start of the reordered array (near the DC coefficient) and lower towards the
higher frequencies. CAVLC takes advantage of this by adapting the choice of
VL |
k****e
发帖数: 337 | 2 所谓的coding efficiency，可以看entropy，也相当于要看 symbol的probability。
context adaptive相当于利用了correlation, 把本来单纯的symbol的probability，转
换成了condtional probability, 也就是相当于转换成了 conditional entropy。
conditional entropy总是比原来的entropy要小(看entropy theory)。相应的 coding
efficiency就高了。 |
d*******n
发帖数: 369 | 3 cool, it really sounds like a insight! thanks alot. |
d*******n
发帖数: 369 | 4 cool, it really sounds like a insight! thanks alot. |
