Wednesday, October 3, 2012

CCD vs CMOS camera

  CCD stands for charge-coupled device; CMOS stands for complimentary metal-oxide semiconductor. A CCD image sensor or a CMOS sensor is used in most digital CCTV cameras. Capturing light and converting it into electrical signals is the main task of the two types of sensor
CCD image sensor is an analog device. These are the chips onto which the light captured by a camcorder's lens is focused. Camcorder processes those signals, then the image is recorded to the camcorder's storage.
CMOS VS CCD
A CMOS imaging chip is a type of active pixel sensor made using the CMOS semiconductor process. Extra circuitry next to each photo sensor converts the light energy to a voltage. Additional circuitry on the chip may be included to convert the voltage to digital data.
Neither technology has a clear advantage in image quality. On one hand, CCD sensors are more susceptible to vertical smear from bright light sources when the sensor is overloaded; high-end frame transfer CCDs in turn do not suffer from this problem. On the other hand, CMOS sensors are susceptible to undesired effects that come as a result of rolling shutter.
CMOS can potentially be implemented with fewer components, use less power, and/or provide faster readout than CCDs. CCD is a more mature technology and is in most respects the equal of CMOS, CMOS sensors are less expensive to manufacture than CCD sensors.
Another hybrid CCD/CMOS architecture, sold under the name "sCMOS", consists of CMOS readout integrated circuits (ROICs) that are bump bonded to a CCD imaging substrate – a technology that was developed for infrared staring arrays and now adapted to silicon-based detector technology. Another approach is to utilize the very fine dimensions available in modern CMOS technology to implement a CCD like structure entirely in CMOS technology. This can be achieved by separating individual poly-silicon gates by a very small gap. These hybrid sensors are still in the research phase, and can potentially harness the benefits of both the CCDs and the CMOS imagers. 

Monday, October 1, 2012

DDNS Service & Dynamic IP Addresses Used in Security Systems

  Many users of surveillance camera system want to view their CCTV cameras remotely over the Internet.  In order to do this, a high-speed Internet connection is needed. Usually, a static or dynamic IP address is assigned by Internet service provider (ISP).  What is the difference between dynamic and static IP address? So, I tell the difference between the two kinds of IP address. Set to an IP address which is unchanged for months or years at a time, this is a static IP address, set to an IP which is only good for a limited time, and which is changed according to the policy set by your ISP's DHCP server, this is a dynamic IP address
If you use a static IP address at your DVR location, you can connect to your security system remotely using the same IP address all the time. If you have a dynamic IP address, things changes because ISP assign IP address randomly.  If you want to track any changes to the dynamic IP, you need subscribe to a dynamic DNS service (DDNS) that keeps track of it for you.  The most popular DDNS service is dyndns.com for free.
When you register with a DDNS service, you can create a host name, you can use hostname to access a website on the Internet.  You then associate that host name with the IP address of your Internet service connection. We can use a router supporting DDNS to do this. Log into your router and locate the DDNS setup screen.  The location may vary by router manufacturer.  Enter your DDNS account settings, including your login, password, and the host name that you registered.  Now, anytime your router detects that your IP address has changed from your ISP, the router will notify the DDNS service about the new IP address.  This allows you to always use the hostname that you registered to connect to your DVR remotely over the Internet.  There is no need to remember or keep track of your IP address.

New Japanese security camera scans 36 million faces per second


  A new Surveillance Camera product has been developed by a Japanese company which can search through a massive amount of data in one second, based on facial recognition technologies.
  If you thought Big Brother had already arrived, Hitachi Kokusai Electric has just kicked the gauge up several notches, in the form of millions of indexes.

  According to DigInfoTV, a Tokyo video news site, Hitachi Kokusai Electric's new development can sift through data on 36 million faces in one second. The report states the technology can find a face matching against either surveillance footage or a photo.
  “This high speed is achieved by detecting faces through image recognition when the footage from the CCTV cameras is recorded, and also by grouping similar faces,” Seiichi Hirai, Hitachi Kokusai Electric researcher told DigInfo TV.
  "We think this surveillance camera system is suitable for customers that have a relatively large-scale surveillance system, such as railways, power companies, law enforcement, and large stores," the company said.
  RT reported Hitachi has used algorithms combined with facial recognition software. Any images captured on the new system is susceptible to a search conducted on other databases to track people and saved in what sounds like a master database of sorts. RT describes it as "Where before authorities would have spent hours trawling through CCTV footage, an individual can now be found in the blink of an eye."
  Reportedly the search results are instant and possible candidates immediately shown to the searcher, although limitations exist, such as the faces must turn within 30 degrees of the camera and be 40 x 40 pixels in size.
  So while this appears to be Hitachi's niche market segment, where does that leave everyone else who will undoubtedly be impacted if these agencies and businesses embrace the new CCTV monitoring system?
  Geekosystem points out, "Of course, the existence of technology that can perform facial recognition on such a scale doesn’t directly translate to immediate and total surveillance of everyone everywhere. It does, on the other hand, make the installation of cameras, lots of cameras, infinitely more useful and justifiable, from a cost-benefit standpoint."
  Then again, lesser scaled versions using biometrics in the past have failed to meet objectives, so in all likelihood, if this new product succeeds in its purpose, it'll depend upon the data being compared against.
  No quote just yet on how much something like this will cost, but it looks like this product will be available sometime next year. If this successfully launches and works as planned, it sounds as if 2013 could perhaps be the year Big Brother truly arrives in style.
  What do you think? Do these types of technologies using stored biometric data help protect society? Does it make you feel more secure?