## 4 Experimental Results
\begin{table}
\begin{tabular}{l c c c c} \hline  & \multicolumn{2}{c}{**Average (\(\pm\)std dev)**} & \multicolumn{2}{c}{**Average (\(\pm\)std dev)**} & \multicolumn{2}{c}{**Comparison**} \\
**Base** & **Payload per Input Byte** & **Payload per Output** & **Map** & **with Expected** \\  & **[bpb]** & **Symbol [bps]** & & **Payload** \\ \hline Base45 & \(0.19754\pm 0.00337\) & \(0.13169\pm 0.00224\) & 1 & + \\ Base45 & \(0.19779\pm 0.00539\) & \(0.13186\pm 0.00359\) & 2 & + \\ Base45 & \(0.19090\pm 0.00313\) & \(0.12727\pm 0.00209\) & 3 & – \\ Base85 & \(0.00834\pm 0.00038\) & \(0.00667\pm 0.00031\) & 1 & + \\ Base85 & \(0.00687\pm 0.00579\) & \(0.00550\pm 0.00469\) & 2 & — \\ Base85 & \(0.00812\pm 0.00360\) & \(0.00650\pm 0.00297\) & 3 & - \\ \hline \end{tabular}
\end{table} 
Table 4: Results of the Base45 and Base85 encodings applied to 500 PNG colour images (average image size 1017.8 KB). \begin{table}
\begin{tabular}{l c c c c} \hline  & **Average (\(\pm\)std dev)** & **Average (\(\pm\)std dev)** & \multicolumn{2}{c}{**Comparison**} \\
**Base** & **Payload per Input Byte** & **Payload per Output** & **Map** & **with Expected** \\  & **[bpb]** & **Symbol [bps]** & & **Payload** \\ \hline Base45 & \(0.22824\pm 0.02025\) & \(0.15216\pm 0.01350\) & 1 & ++ \\ Base45 & \(0.25218\pm 0.08942\) & \(0.16812\pm 0.05961\) & 2 & ++ \\ Base45 & \(0.11456\pm 0.06031\) & \(0.07638\pm 0.04021\) & 3 & – \\ Base85 & \(0.00844\pm 0.00099\) & \(0.00675\pm 0.00082\) & 1 & + \\ Base85 & \(0.01287\pm 0.01747\) & \(0.01031\pm 0.01402\) & 2 & ++ \\ Base85 & \(0.00660\pm 0.01039\) & \(0.00528\pm 0.00831\) & 3 & \(--\) \\ \hline \end{tabular}
\end{table} 
Table 3: Results of the Base45 and Base85 encodings applied to 500 TIFF colour images (average image size 1297.4 KB). \begin{table}
\begin{tabular}{l c c c} \hline  & **Average (\(\pm\)std dev)** & **Average (\(\pm\)std dev)** & \multicolumn{2}{c}{**Comparison**} \\
**Base** & **Payload per Input Byte** & **Payload per Output** & **Map** & **with Expected** \\  & **[bpb]** & **Symbol [bps]** & & **Payload** \\ \hline Base45 & \(0.19630\pm 0.01242\) & \(0.13087\pm 0.00828\) & 1 & + \\ Base45 & \(0.19785\pm 0.01709\) & \(0.13190\pm 0.01139\) & 2 & + \\ Base45 & \(0.19191\pm 0.01683\) & \(0.12794\pm 0.01122\) & 3 & – \\ Base85 & \(0.00871\pm 0.00150\) & \(0.00697\pm 0.00123\) & 1 & + \\ Base85 & \(0.01066\pm 0.00734\) & \(0.00855\pm 0.00593\) & 2 & ++ \\ Base85 & \(0.00858\pm 0.00189\) & \(0.00687\pm 0.00150\) & 3 & + \\ \hline \end{tabular}
\end{table} 
Table 5: Results of the Base45 and Base85 encodings applied to 75 compressed files (format.zip). We also performed an evaluation for the embedding into Base45 encoded files (for Base85 encoded files we did not perform such a test, because the statistics required a very large number of data and a histogram for \(2^{32}\) entries). By using a mapping \(\varphi\) onto the set of the most probable sequences in \(\mathcal{C}\) for the set of 500 JPEG images, the resulting payload is 0.262 ppb, that is significantly larger than with the uniform distribution. Analogously, an optimized mapping for a set of 212 compressed files resulted in a payload of 0.2038 ppb. In this case, it is much closer to the theorical payload (0.1952 ppb) for uniform input data distribution. Obviously, the function \(\varphi\) specifying the mapping onto the most probable sequences in \(\mathcal{C}\) needs to be shared between encoder and decoder.