Understanding Picture Quality

In the last post on 7th April 2011 we had covered the different technologies available to you and a broad idea of the kind of output you can get from them. At Dee Cee Security Systems Pvt. Ltd. we are committed to suggest you the right technology and the right solution which exceeds your expectations and is within your budget.

Here we will give you a idea of the main aspect of CCTV Cameras which every buyer is looking for but gets confused when he sees technical words like CIF, 4CIF, D1,etc.

Before we go into understanding the above, you need to understand one word which "PIXEL". What is a Pixel?, while you hear megapixel, HDTV and other terminologies nowadays, very few people understand that they are based on amount of pixels they support.

In simple terms, PIXEL stands for Smallest Picture Element. See the below picture:

Image Source: Wikipedia.com

What you see above is a Monitor on the left. On the right side you see a image which is zoomed in version of the image. The selected area is shown as a square on the left side.The element has been red colored and named as Pixel. That is a Pixel. If we name that Pixel as P0 and the next one as P1,P2,P3...... and so..on... then we would get the image resolution. A image resolution bascially refelcts the total number of pixels the image.

Do understand the number of pixels is directly proportional to quality of picture. So higher the number of pixels better the picture clarity.

Following table gives you a idea of the number of pixels expected from a Analog Camera.

Table of Analog Video Resolutions (in pixels)
Format	NTSC-Based (in pixels)	PAL-Based (in pixels)
QCIF	176 × 120	176 × 144
CIF	352 × 240	352 × 288
2CIF	704 x 240	704 x 288
4CIF	704 × 480	704 × 576
D1	720 × 480	720 × 576

To understand the above, i will give you example, QCIF which gives you a resolution of 176 X 144 in PAL( used in Asian Countries) means it will give you a resolution of  176 Pixels X 144 Pixels horizontally and vertically. Thus as we go higher the image size increases.

The following is table of Digital Video Resolution ( or IP Camera Resolution):

Size/ Format	Pixels
QQVGA	160x120
QVGA	320x240
VGA	640x480
HDTV	1280x720
1M	1280x960
1M	1280x1024
2M	1600x1200
HDTV	1920x1080
3M	2048x1536

So you can see the number can go a lot higher in Digital Video Resolution compared to Analog Video Resolution thus offering you Best picture Quality.

You can get in touch with me at rohit at omnipolis.in for any clarifications.

Placement of CCTV Camera for Surveillance

In this article i would like to cover identifying the need for placement of CCTV Cameras for Effective Surveillance. While realization and acceptance for need of CCTV Cameras may be a good step in the wake to have multiple eyes and keep theft under control, improper placement can lead to expenditure going over the roof.

Basic principle towards proper placement of CCTV Cameras can be divided under two categories:
1. Identify the Center Points
2. Focus on Main Assets

1. Identify the Center Points: Center Points can be defined as points of intersection & paths through which people, objects or vehicles have to pass in order to enter/exit a particular premises. Examples are Entrances, Hallways, Exit Points, Car Parking, Staircases.

2. Focus on Physical Assets: Main assets are the objects or places where monitoring is necessary. Objects such as expensive jewellery or artifact, merchandise for retail or expensive portable machinery and places such as points of cash transactions(cash counters/registers), reception, server room, store room and places which house a asset valuable to the organization.

The above should help in conducting a security survey and give you a cost effective solution. In the next article i will cover how to do the selection of cameras for different locations.

@Rohit Jain - Omnipolis