This paper explores the challenges Broadcasters face when assessing video quality. Many factors affect the video before it gets to the TV: compression, image processing, scaling, decoding, transmission, etc.

Video processing and compression algorithms change the characteristics of the original program in the quest of reducing the bandwidth needed to send the programming information to the home. The art is to do this without allowing the audience to perceive a change in video quality. Successful video processing and compression algorithms perform the desired modifications while presenting a result to the viewer that, subjectively, looks natural and realistic. This sounds difficult, but it is necessary when transmitting many channels of high-quality programming.

Each broadcaster - traditional or web caster - must deal with rapidly changing varieties of programming, new video processing algorithms, and new compression algorithms. Video processing and compression companies continuously invent sophisticated ways to reduce the huge bandwidth requirements to manageable levels. How can broadcasters know if a new algorithm is better than their current choice?

Broadcasters invite the various video processing and compression companies into their R&D facilities, and perform side-by-side tests also known as a "bake-off". Each vendor starts with the same source material, and does their best to reduce the bandwidth while keeping the video quality high.

The broadcaster shows the results to a group of experts and asks them, which one is the best. This is termed subjective video analysis, and it measures the overall perceived video quality. The most commonly used video quality evaluation method is the Mean Opinion Score (MOS), recommended by the ITU. It consists in having several experts viewing a known distorted video sequences in order to rate its quality, according to a predefined quality scale. By doing this the expert viewers are trained to build a mapping between the quality scale and a set of processed video sequences. After the "training" is complete, the subjects are then asked to rate the new video processing algorithms.

Simply stated, the test setup is
* Start with a known video sequence.
* New Video Processing system alters the video sequence.
* Display the original and processed video sequences.
* Bring in experts to subjectively vote.

Complexity arises as
* New Video Processing systems may need new equipment to playback the video sequences.
* The original and processed video sequences should be displayed in random orders.
* Expert viewers are expensive and do not produce repeatable results.

Easier Solution
To streamline the process, equipment for video quality testing needs to be defined, which can capture, play, and analyze any two video sequences. Further, as new input/output modules are continuously under development, the test equipment should use an open-architecture approach to ease upgradeability.

Letters are being sent to everyone in the area explaining how the Digital TV switchover will work and what they need to do to keep viewing TV. On screen messages will also appear on analogue channels from May warning viewers that the analogue signal will be turned off in the next few months.

The Digital TV switchover will then be carried out region by region, with the rest of the Borders the next to have its analogue signal switched off, beginning at the end of 2008. By the end of 2012 the analogue signal will have been turned off across the whole of the country meaning everyone must have switched over to Digital TV in order to keep viewing TV.

•Barbell Biceps Curl - This exercise is perhaps the most commonly executed in the wrong form and causing injuries that people don't even know why they are injured. In every gym, you will see people swinging their barbells with their body rocking thru and fro in the movements.


The rocking movement places tremendous stress on the shoulder joint which is the most unstable joint in the human body and the lower back. Over time, the shoulder joints and lower back will pay a heavy price for the wrong form and technique used during the lift.


Other common bodybuilding exercises which are often wrongly executed are the lat pull down, bench press, leg extension, military press and list goes on.


So the next time when you have backache or joint pain, don't blame it on other causes if you are a bodybuilder and that you lift weights often. Just reflect on the weightlifting exercises you are doing and examined them as to whether they are the cause of your injuries.


Better yet, hire a personal trainer or a bodybuilding book with picture illustration and description to learn how to lift weights in the correct form and technique to prevent common and serious weight lifting injuries.