Frequently Asked Question (Faq); About I-Rec B104'S Feature - WebGate i-Rec B104 Installation Manual

Appendix

#1. Frequently Asked Question (FAQ)

#1.1. About i-Rec B104's Feature

What is i-Rec B104?
i-Rec B104 is a 4-channel box style DVR with a Web server of embedded Linux, a
networking device, and a HDD (HDD Rack). Since i-Rec B104 is a Web server, it does not
need to be connected to other servers. By installing an i-Rec B104 in remote locations, you
can remotely record and monitor the place.
What preparations are needed to install?
No equipment is necessary other than power and network cable
Which algorithm is used to compress digital images?
i-Rec B104 uses Wavelet algorithm to compress digital images. Wavelet is a still-image
based compression algorithm. Still-image based means that i-Rec B104 captures still
pictures. JPEG, the standard algorithm in image compression, is also based on still-image.
i-Rec B104 records and transmits frames rapidly so as to make still images move as in a
motion picture.
MPEG is another standard in image compression, but it is based on motion pictures and
does not capture still images.
What is the difference between Wavelet algorithm and JPEG in compressing digital
images?
Wavelet is more efficient than JPEG by 30-300%. Higher efficiency of Wavelet comes from
its encoding method. Wavelet algorithm uses DWT (Discrete Wavelet Transform), while
JPEG uses DCT (Discrete Cosine Transform). Due to its efficiency, Wavelet will be adopted
as standard in digital image compressing by the new JPEG2000 standard.
Can i-Rec B104 support multi users at the same time?
It is possible for an administrator and 4 general users to simultaneously access for real-time
monitoring and playback.
WEBGATE Inc.
2003. 06. 30 (v 1.4)
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