Page 452 - Mechatronics for Safety, Security and Dependability in a New Era

Ch88-I044963.fm Page 436 Tuesday, August 1, 2006 5:32 PM
Ch88-I044963.fm
436
436 Page 436 Tuesday, August 1, 2006 5:32 PM
archive security based on ISO17799 and 15408 are briefly mentioned in section 6, then conclusion and
future issues will mention in the last section.

2. ARCHIVE SYSTEM
The core of the archive system is a large scale tape feed robot that can store 7200 professional use video
cassettes of DVC-PRO format. This system uses a DVD server of medium speed and medium capacity and
an HDD (Hard Disc Drive) server for high speed and small capacity storage. Fig. 1 shows the total archive
and delivery system and Fig.2 shows the outlook of the tape feed robot.
This archive system uses video sequences in DB format (SMPTE 306m, 25Mbps and 50Mbps) with
high picture quality suitable for broadcasting use to store pictures on both the large scale tape feed robot and
the high sped access type HDD server. Then this video contents are distributed through the network, data
stream of this sequence is formatted with MPEG-1 or MPEG-2, 4. Thus DV formatted data are used for
video image storage and MPEG-1 formatted data with low bit volume, are used for distribution of image
sequences for browsing of digest videos both in-house and on the outside network. The data stream from
the archive system in converted from SD (Standard Definition Video Stream) to MPEG-2 on MPEG -TS
(Transfer Stream) using the FTP (File Transfer Protocol) and this stream is run through the distribution
network for contents distribution to the other security network [1-4].
The system has the visual retrieval interface, shown in Fig. 3, which shows 32 or 64 thumbnail video
simultaneously hence 64 contents can check at the same time.
3. WATER MARK

The digital watermark technology is one of the important issues to embed additional information such
as the metadata to the video .
In the large amount of video database, separate database manager such as oracle system or SQL server are
used.
But in such system, the data mismatch caused by human dispersing or operation error. One of the
effective method to preserve the additional information relate to the video signal is digital watermarking. In
this method additional data such as metadata, time-code, and copy-right information are added on the video
data themselves on the lower bit area of the DCT coefficient of the video data.
Fig. 4 shows one of our original water marking method in which low space frequency area on DCT is
aimed at the data embedding as well as high frequency area [9, 10].
The lower and higher part of the spatial frequency area are not very sensitive for the human eyesight hence
the embedding noise is less visible and the S/N ratio can be improved on human eyesight. Fig 4 shows the
experimental result of embedded disaster information on the recorded image. Fig. 3 shows an example of
the S/N ratio of the video on which watermark is embedded[5-8].
4. MPEG-7 OVER CONTENTS ID
In order to solve above issues, we focused on the application of MPEG-7 description and the cid
compliant to cIDf, and we decided to adopt MPEG-7 descriptor to describe contents feature on our archive
system. The main purposes are to realize efficient retrieval for anybody who want the contents. In the
conventional method, keywords that were easy to understand for that familiar to regional Yamagata area,
where YRC is located, were attached to the contents. However, in general, assuming that those from other
outside area would try to retrieve the contents, easy retrieval will not always be done from these localized
keywords.
To realize the system allowing reuse of the content, we envisage the interoperability such as moving whole
contents in our system to other databases. MPEG-7 is the content description system standardized in
ISO/I EC JTC-1 SC29/WG11 (MPEG), and is the important technology for the era of broadband digital
network. Furthermore, it is the only tool that can offer standardized representation scheme of content related
metadata.[9-ll].

5. FORMAT OF THE INDEX
OF PREVENTION FOR DISASTER
In order to apply Mpeg-7 metadata to the disaster database, we considered both the fact that the video
contents we currently have is the center of our system and the practicability, and decided to adopt Method b.