# An Enhanced Adaptive Block Truncation Coding with Edge Quantization Scheme +
## 4 Experiment and Comparison
### Experimental Results
The original image is given in Figure 1a, and the reconstructed images from AMBTC, MBTC, ABTC-EQ, Scheme A, Scheme B-I,  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Tested**} & \multirow{2}{*}{**Method**} & \multicolumn{3}{c}{**Block Size (4 \(\times\) 4) Pixels**} & \multicolumn{3}{c}{**Block Size (6 \(\times\) 6) Pixels**} & \multicolumn{3}{c}{**Block Size (8 \(\times\) 8) Pixels**} \\ \cline{3-14}  & & **PSNR** & **CR** & **SSIM** & **FSIM** & **PSNR** & **CR** & **SSIM** & **FSIM** & **PSNR** & **CR** & **SSIM** & **FSIM** \\ \hline \multirow{10}{*}{Lena} & AMBTC & 33.42 & 4.00 & 0.9901 & 0.9946 & 31.30 & 5.54 & 0.9753 & 0.9814 & 29.99 & 6.40 & 0.9587 & 0.9697 \\  & MBTC & 33.87 & 4.00 & 0.9901 & 0.9942 & 31.77 & 5.54 & 0.9763 & 0.9800 & 30.55 & 6.40 & 0.9614 & 0.9647 \\  & ABTC-EQ & 37.49 & 3.09 & 0.9944 & 0.9973 & 35.29 & 3.98 & 0.9885 & 0.9915 & 34.07 & 4.36 & 0.9826 & 0.9855 \\  & Scheme A & 37.49 & 3.24 & 0.9944 & 0.9973 & 35.29 & 4.29 & 0.9885 & 0.9915 & 34.07 & 4.80 & 0.9826 & 0.9855 \\  & Scheme B-I & 37.47 & 3.33 & 0.9945 & 0.9974 & 35.28 & 4.38 & 0.9886 & 0.9917 & 34.05 & 4.87 & 0.9827 & 0.9857 \\  & Scheme B-II & 37.39 & 3.42 & 0.9940 & 0.9970 & 35.21 & 4.47 & 0.9879 & 0.9911 & 34.00 & 4.94 & 0.9819 & 0.9849 \\  & Scheme B-III & 37.14 & 3.52 & 0.9928 & 0.9962 & 35.01 & 4.56 & 0.9862 & 0.9896 & 33.82 & 5.01 & 0.9799 & 0.9832 \\  & Scheme B-IV & 35.96 & 3.62 & 0.9869 & 0.9917 & 34.17 & 4.66 & 0.9787 & 0.9841 & 33.13 & 5.09 & 0.9717 & 0.9770 \\  & Scheme C & 39.62 & 3.09 & 0.9954 & 0.9979 & 37.40 & 3.98 & 0.9911 & 0.9939 & 36.26 & 4.36 & 0.9874 & 0.9907 \\ \hline \multirow{10}{*}{Butterfly} & AMBTC & 32.26 & 4.00 & 0.9877 & 0.9944 & 30.27 & 5.54 & 0.9702 & 0.9818 & 20.99 & 6.40 & 0.9520 & 0.9687 \\  & MBTC & 32.66 & 4.00 & 0.9877 & 0.9939 & 30.74 & 5.54 & 0.9721 & 0.8066 & 29.61 & 6.40 & 0.9526 & 0.9644 \\  & ABTC-EQ & 36.26 & 2.99 & 0.9939 & 0.9971 & 34.20 & 3.78 & 0.9866 & 0.9908 & 33.04 & 0.49 & 0.9793 & 0.9845 \\  & Scheme A & 36.26 & 3.15 & 0.9939 & 0.9971 & 34.20 & 4.12 & 0.9866 & 0.9908 & 33.04 & 4.57 & 0.9793 & 0.9845 \\  & Scheme B-I & 36.24 & 3.25 & 0.9939 & 0.9971 & 34.18 & 4.21 & 0.9867 & 0.9910 & 33.02 & 4.64 & 0.9795 & 0.9847 \\  & Scheme B-II & 36.17 & 3.35 & 0.9935 & 0.9967 & 34.12 & 4.31 & 0.9861 & 0.9904 & 32.97 & 4.72 & 0.9786 & 0.9840 \\  & Scheme B-III & 35.96 & 3.46 & 0.9925 & 0.9961 & 33.96 & 4.42 & 0.9846 & 0.9891 & 32.81 & 4.80 & 0.9769 & 0.9823 \\  & Scheme B-IV & 34.99 & 3.58 & 0.9874 & 0.9922 & 33.24 & 4.53 & 0.9779 & 0.9835 & 32.19 & 4.89 & 0.9692 & 0.9759 \\  & Scheme C & 38.32 & 2.99 & 0.9951 & 0.9976 & 36.29 & 3.78 & 0.9901 & 0.9933 & 35.19 & 4.09 & 0.9852 & 0.9895 \\ \hline \multirow{10}{*}{Cameraman} & AMBTC & 32.13 & 4.00 & 0.9920 & 0.9934 & 29.82 & 5.54 & 0.9782 & 0.9762 & 28.67 & 6.40 & 0.9659 & 0.9609 \\  & MBTC & 32.43 & 4.00 & 0.9915 & 0.9941 & 30.24 & 5.54 & 0.9795 & 0.9739 & 29.13 & 6.40 & 0.9678 & 0.9559 \\  & ABTC-EQ & 36.73 & 3.12 & 0.9961 & 0.9971 & 34.33 & 4.07 & 0.9914 & 0.9909 & 33.12 & 4.56 & 0.9872 & 0.9844 \\  & Scheme A & 36.73 & 3.26 & 0.9961 & 0.9971 & 34.33 & 4.37 & 0.9914 & 0.9909 & 33.12 & 4.97 & 0.9872 & 0.9844 \\  & Scheme B-I & 36.71 & 3.35 & 0.9961 & 0.9972 & 34.31 & 4.45 & 0.9916 & 0.9911 & 33.11 & 5.03 & 0.9874 & 0.9848 \\  & Scheme B-II & 36.65 & 3.44 & 0.9957 & 0.9967 & 34.27 & 4.54 & 0.991 Scheme B-II, Scheme B-III, Scheme B-IV, and Scheme C using (4 \(\times\) 4) blocks are, respectively, illustrated in Figure 1b-j. Scheme C (Figure 1j) has the best PSNR 39.62 dB. ABTC-EQ and the proposed schemes deal with edged blocks and thus may have better performance near edges. The edge images of the original image Cameraman and the reconstructed images from AMBTC, MBTC, ABTC-EQ, and Scheme C are shown in Figure 2. The non-edge based schemes (AMBTC and MBTC) do not retain the details of selected portions, as shown in the dashed circle. However, both Scheme C and ABTC-EQ have better details. Moreover, it is observed that Scheme C demonstrates more edges in the circle area than ABTC-EQ.