Author: Bob Mesnik

The History of Video Surveillance

Evolution from Closed Circuit TV to Ubiquitous IP Camera Surveillance

By Bob Mesnik

From the early beginnings of Closed Circuit Television (CCTV), it was somewhat controversial.  It was designed to increase our security and safety, but does it threaten our privacy?  How has video surveillance changed over the years?  This article reviews the history of surveillance and how it has evolved into a technology that has become part of our lives.

v2 rocket launch

History

Video surveillance is not new; it has been around for quite a while.  One of the first recorded application for closed circuit television system (CCTV) was back in 1942.  It was used to view the launch of V2 rockets in Germany.

In the US, commercial surveillance applications began around 1947.  In 1957 a number of companies such as General Precision Labs (GPL division), provided CCTV camera systems for education, medical and industrial applications.

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How to Select the Right IP Video Intercom

Selecting the best video Intercom for your application.

By Bob Mesnik

IP Intercom over cloud

The audio and video quality are important features when selecting IP video intercoms.  You can select Video Intercoms that connect through IP cameras to Windows workstations, or others that communicate through cloud servers to smartphones.

The right type of intercom depends on your application.  Intercoms, that connect to Video Management Software (VMS), integrate with your IP camera surveillance system.  The other type of video intercoms connect through the cloud to a smartphone rather than a Windows computer.

Both systems integrate with IP door access control systems and allow you to grant access to visitors and anyone that doesn’t have a credential.

In a previous article, “How to Select the Best IP Intercom” we described the features and functions that should be considered when selecting audio IP intercoms.  This article focuses on the intercoms that include video.

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How to Select the Best IP Intercom

Old Intercom

What are the features and functions to look for when selecting your IP intercom?

By Bob Mesnik

IP intercoms are simple in concept, but complex in practice.  They are easy to install, but there are many options to consider. We have evaluated a number of different types of intercoms, and found that the more successful products are provided by those who understand the black art of audio, rather than science of networks.

IP intercoms are simple in concept, but complex in practice.  They are easy to install, but there are many options to consider.  We have evaluated a number of different types of intercoms, and found that the more successful products are provided by those who understand the black art of audio, rather than science of networks.

What are the most important features and functions for an IP intercom system?

Of course, the sound quality of all the intercoms is one of the most important aspects to consider.  Reliable communication is another important capability.  After all, controlling a door is one aspect of your overall security.  Many of the other features and functions depend on the application.  For example, some intercoms just include two-way audio, while others also include video.   Some can control an electric lock or interface to an IP door access control system.  You may need a system that allows you to communicate with a Windows computer, or one that communicates with your smart phone.  Here are the features and functions you should consider when selecting your IP intercom system.

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Technical Jokes and Cartoons – 18

Math and Science for Engineers, and Others:

As an engineer, I found that it was important to learn certain basic mathematical concepts. Since, you also may need to know about scientific things, I put together some examples.  By the way, all these diagrams are from Instachaaz,

Probability Density Function:  The probability histogram shows how likely it is for something to occur over time, or over some other variable. For example:

Cartoon-Popularity-Things-xkcd
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Detection, Recognition, and Identification – Thermal vs. Optical IP Camera

Resolution required for Recognition, Detection, Identification depends on the type of camera

By Bob Mesnik

Thermal Camera Image

There is some confusion in the industry about how much camera resolution is required to detect an object, recognize the type of object, or identify exactly what or who it is.  The criteria are different between thermal and optical cameras.  Resolution for thermal cameras and optical IP cameras are measured differently.

For example, when defining the performance of a thermal camera we use the Johnson Criteria of “detection”, “recognition” and “identification” (DRI). 

On the other hand, IP camera resolution performance is usually defined by the number of pixels in the sensor, and we are usually interested in the ability to identify a person.

How much resolution do you need?  This article compares how resolution is defined using thermal and optical technologies.

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What IP Camera Resolution Do You Need?

Resolution-of-camera

How to determine the resolution required for your IP camera system
By Bob Mesnik

How much resolution do you need?  It depends on what you need to see. Do you want to identify who stole your car, or just see that there’s a dog in your yard again.

It’s very important to first determine exactly what you want to see, because it will affect how much your IP camera system costs.

This article reviews the amount of resolution required to recognize objects such as people, vehicles, license plates, or even a small crack in a wall.

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Technical Jokes and Cartoons 17

Cartoon-Dr-Photoshop

Definition of an Engineer:
Someone who solves a problem you had no idea you had, and does it in a way you don’t understand.

Tech support Issues:

Helpdesk: What’s on your monitor now ma’am?
Customer: A teddy bear my boyfriend bought for me in the supermarket.

During a recent password audit, it was found that a blonde was using the following password:

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How Power Over Ethernet Works

PoE makes installation very easy

By Bob Mesnik

This article has been updated on 10/4/2018 to reflect the new PoE injectors available.

Many network-attached devices, such as IP cameras, VoIP phones, WiFi radios, and IP door readers use power over Ethernet (PoE).  The single network cable transfers both data and power to the device making installation very simple.  The data uses one set of wires, while the power uses another set of wires in the network cable.

PoE Injector Diagram
PoE Injector Diagram
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Technical Jokes and Cartoons 16

Cartoon-xkcd-Dog Domestication

The real art of conversation is not only to say the right thing at the right time, but also to leave unsaid the wrong thing at the tempting moment.

The older you get, the tougher it is to lose weight, because by then your body and your fat have gotten to be really good friends.

The easiest way to find something lost around the house is to buy a replacement.

He who hesitates is probably right.

If you think there is good in everybody, you haven’t met everybody.

If you can smile when things go wrong, you have someone in mind to blame.

The sole purpose of a child’s middle name is so he can tell when he’s really in trouble.

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