From VCR to Digitalization
Since the introduction of VCR surveillance recorder in the early
1970s, applications of analog CCTV systems had increased with
each passing year. The technology continued to develop,
distribute and improve until 1995s. However, nowadays,
enterprises, casinos, large retail shops, freight centers,
franchises and most government buildings worldwide use VCR-based
recording systems to deter crime and aid in criminal
Method for recording video on tape with tape-recording equipment is
an analog type. Namely, each camera connect to one device
(Multiplexer) to split all the cameras’ image, and then output them
on a CRT monitor, and use VHS to record the image on video tape.
Operator then uses storage rack to protect tapes from humidity.
HIGH SETUP AND RUNNING COST
As the whole system involved many independent equipments,
Multiplexer, TV, several VCRs, immense amount of tapes and expensive
storage space that led to high running and operating costs.
LOW VIDEO QUALITY
Tapes would wear or tear over time, image would distort, video
integrity is hard to preserve over time due to changing climate and
humidity. This is an ever-present problem of analog tapes.
User may have to review all the tape to find one specific image.
And large storage space is required for tapes. Spaces are noticeably
expensive in some cities such as Hong Kong. Keeping records for a
long period of time, such as one year, is impossible.
Systems need operator to change tape frequently and perform
system maintenance, and operator must be at the site to acknowledge
All the records stored on tapes. Viewer must go to the site and
take the tapes to see what was going on. When camera number has to
be increased, that also led to the problem of cabling, and
troublesome modification of the whole system.
problems stated above found no solutions until the boom of digital
era. From cameras to digital cameras, from tapes to CD or Hard Disk,
from CRT to LCD, surveillance system also gets the same change -
VCRs to DVRs (Digital Video Recorder)
. From 2002 to 2003, DVRs constitutes up to 75% of new CCTV systems
in United States, especially after the terror attacks 9/11. With
continuous product improvement come better-functioning products,
lower costs, and a steadily growing customer base, products based on
digital technology begins to dominate the entire CCTV market.
We now use CD to replace
analog tapes, and all the captured images from cameras distribute
over the Internet, user can monitor from anywhere at any time.
Digital Solutions: DVR [Digital Video Recorder]
Network DVR Whitepaper