This paper introduces a modified minimum risk Bayesian classification framework employing a relative SATD that indicates how different SATDs are in a set of intra prediction modes.
where D_Had is the SATD, R_mode represents the number of bits for a prediction mode, and C is the RMD cost.
In their work, if a mode with the minimal SATD cost is one of the MPMs, the mode is directly decided as being the best mode instead of performing the RDO process.
 reduced candidates of rate-distortion optimized quantization based on SATD with 2:1 down-sampled prediction residual.
It is a fact that the RMD cost is not firmly reliable in the sense of the RDO because it utilizes SATD instead of the kinds of discrete cosine transform (DCT) or discrete sine transform (DST) used in HEVC.
[L.sub.HAD] = SATD + [[lambda].sub.pred]* [Bit.sub.p]s (1)
In order to make a balance of the computation complexity and classification performance, we choose the entropy of Gray-Scale Difference Statistics (GDS) and the minimum of SATD  as two important features to design the classifier.
In the second step, the key of the task is to find two useful features (entropy on account of GDS, the minimum value of SATD after intra prediction) trained by the data mining tool, Waikato Environment for Knowledge Analysis (WEKA) .
To achieve more previse judgment, a good deal of statistics have already been computed, such as the entropy of CU blocks, the mean of CU blocks, the variance of the CU blocks, the entropy of GDS of CU blocks, and the prediction residual between the original block and the reconstruction block, that is the minimum value of SATD.
Wang, "Intra frame rate control based on SATD
," in Proc.
[D.sub.SATD] is the Sum of Absolute Transformed Difference (SATD
) which calculates the sum of abolute value of hadamard transformed coefficients of the residual signal, [R.sub.mode] is the number of bits to encode mode information, [D.sub.rec] is the distortion of the reconstructed block, [R.sub.total] is the total number of bits to encode current block and [lambda] is the Lagrangian multiplier.