# DTV Essential Hidden Area Decoder for DTV Broadcasting
## 4 Experimental Results
### Video Quality in MPEG CBR  
The whole program is encoded at a bit rate of 13.0 Mbps and 17.5 Mbps using an MPEG-2 video encoder. Actually, 13.0 Mbps is used for multi-mode service, and 17.5 Mbps is adopted for single-program service via terrestrial HDTV broadcasters [22].  
The proposed DEHA decoder decodes and overlays the DEHA image on the active video to a checked board pattern or QR code, as shown in Figure 14.  
The 16 \(\times\) 15 checked board pattern is useful to analyze the DEHA image in conventional HDTV broadcasting, as shown in Figures 13 and 14. Three-digit values assist us in decoding the DEHA for confirmation of the proposed decoder, and the DEHA text and QR code help us to read the technical metadata.  
The video quality score of those sequences was collected for PSNR quality comparison within active 1920 \(\times\) 1080 regions except the DEHA. The Peak Signal to Noise Ratio (PSNR), which gives the amount of difference between the original and the processed pictures, is a commonly used objective measure of the quality of a video segment before and after compression. The result of the video quality evaluation is shown in Table 4.  
Figure 13: The test configuration for DEHA utilization.  
\begin{table}
\begin{tabular}{c c c} \hline
**Sequence Name** & **Duration [Frames]** & **Coding Difficulty** \\ \hline Crowd Run & 250 & Difficult \\ Park Joy & 250 & Difficult \\ Ducks Takeoff & 250 & Difficult \\ Into Tree & 250 & Easy \\ Old Town Cross & 250 & Easy \\ \hline \end{tabular}
\end{table}
Table 3: Test sequences for DEHA decoder [21].  
Under all conditions, the average quality of the proposed method was slightly neglectable lower or better than that of the original MPEG-2 video compression. This was due to the difference in the creation of the DEHA between the last line copy in the original MPEG video compression and the block image in the proposed method.  
The average quality of technical metadata using the check pattern block is good enough for no recovery error over 50 dB. Based on the results of video quality evaluation,  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sequence** & **Bit Rate** & **Reference Mode** & **Proposed \({}^{*}\)** & **Difference** \\ \hline \multirow{3}{*}{Crowd Run} & 17.5 & 30.01824 & 30.1757 (70.657) & \(-\)0.0067 \\  & 13.0 & 29.0613 & 29.0536 (71.193) & \(-\)0.0077 \\ \multirow{3}{*}{Park Joy} & 17.5 & 28.1710 & 28.1716 (98.460) & 0.0006 \\  & 13.0 & 27.2476 & 27.2464 (99.063) & \(-\)0.0012 \\ \multirow{3}{*}{Ducks Takeoff} & 17.5 & 27.6039 & 27.6043 (46.472) & 0.0004 \\  & 13.0 & 26.7982 & 26.7952 (50.254) & \(-\)0.0030 \\ \multirow{3}{*}{Into Tree} & 17.5 & 35.0548 & 35.0881 (93.705) & 0.0013 \\  & 13.0 & 34.4787 & 34.4971 (93.542) & 0.0184 \\ \multirow{3}{*}{Old Town Cross} & 17.5 & 34.9478 & 34.9437 (58.470) & \(-\)0.0011 \\  & 13.0 & 34.4419 & 34.4365 (56.594) & \(-\)0.0054 \\ \hline \hline \end{tabular} \({}^{*}\)PSNR of active region (DEHA).  
\end{table}
Table 4: Average PSNR for DEHA utilization.  
Figure 14: Decoded DEHA results: (**a**) 453 rd frame of Park Joy sequence and (**b**) 67 th frame of Into Tree sequence.  
the proposed metadata transfer to block image method through the DEHA does not have an effect on quality during video compression.  
To further analyze the results presented in Table 4 and examine maximum and minimum values, trends, etc., we have included the active region PSNR of the Old Town Cross video sequence Figure 15.  
The difference in image quality per frame is less than \(\pm\)0.0011 dB, and the proposed method shows no change in image quality compared to the existing method.