The variation of compression ratio with predictor order is shown in figure 44.
Figure 44: Variation of compression ratio with predictor order for a polynomial and general linear predictor
Note that there is considerable compression without a predictor. This is because the prediction error is non-uniform and therefore may be entropy coded. The distribution of prediction errors is shown in figure 45.
Figure 45: The probability density function for the prediction error and the Gaussian and Laplacian distributions