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Originally posted by peacock1

Hi Friends,
I was shopping for some accessories required for the TV, when the associzte recommended me a calibration CD for the new TV, Can any one explain in details the need to perform the calibration using the CD.
Thanks for your time

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I will start here with a very small explanation of the facts as they stand in the Digital TV system. Then I will tell you where we are and after that a little bit more into the future of TV's.

YCbCr and RGB ..: (Red Green Blue) The dense ness or the richness in each colour etc., is explained here.

All video discs, including Blu-ray, DVD and Video CDs, are encoded as YCbCr. While many displays accept RGB as well as YCbCr, RGB is generally reserved for output to computer monitors. RGB has a data range of 0-255. The 0-255 essentially refers to the number of colors that are available and R, G, and B, refer to Red, Green, and Blue respectively. With this color setting, each of the colors is given equal weight (which translates into equal bandwidth). In a YCbCr system, the luminance (The Brightness) information is transmitted separately and a color difference system is used to derive green. In practical application YCbCr is no different than RGB in terms of quality, when done correctly.

FROM THE CD,DVD and Digital CAMCORDERS.. We separate the Digital and Analog..:
Technical Note: YCbCr vs. YPbPr. : There is often confusion regarding YCbCr and YPbPr, however it is very easy to understand the difference. YCbCr is simply the digital "component video" format that is used in DVDs, digital TV and Video CDs. Digital camcorders (MiniDV, DV, Digital Betacam, etc.) output YCbCr over interfaces such as FireWire or SDI.
YPbPr is simply the analogue version which manifests itself in the form of the three (red, green and blue) RCA connections on most displays (referred to as "component video". Where analogue YPbPr uses three cables for connectivity, digital YCbCr uses only one.

YCbCr has a native data range of 16-235 (though it technically can do 0-255, but more on that later). The difference? Well, while you would think that RGB and its 0-255 would have a greater amount of color, the discs we all watch are mastered at the YCbCr 16-235 levels. In keeping with our definition of accuracy, the best thing you can do is match the original - this avoids interpolation and possible distortion of the original color and image.

Many of your displays can accept a RGB 0-255 signal. However, if you are using your receiver as an HDMI switcher, there may be a bottleneck. For some reason, many receiver manufacturers have strictly limited their receiver HDMI inputs to a 16-235 range for RGB. This means that if you set your source to output RGB, it will be sending a signal to your receiver that will be truncated before it is sent to the display. If you use this signal to calibrate your black levels, your black levels will be off and it's likely you won't see the Blacker-than-Black pattern from test discs.

With xvYCC, the range is again extended to 0-255 as is expected, since digital TVs have no under- or over-shoot as did analogue television signals. This will effectively override (in theory) any RGB or YCbCr settings on your source, AV receiver, or display. The idea is that the xvYCC color gamut is only effective when all components in a chain support it. While several AV receivers and displays support xvYCC color space, currently only the PlayStation3 provides xvYCC as a source. Here's where it gets dicey: The Blu-ray specification for movies (BD-ROM) does not support Deep Color or the new xvYCC color space. Oops.

I'll say it again: Blu-ray and HD DVD movie formats are limited to 8-bit 4:2:0 YCbCr. To our knowledge, there is no move to add xvYCC expanded color capability to the BD-ROM specification. In addition, issues of backwards compatibility would be extremely difficult to overcome, rendering any new 10-bit or higher formats unplayable on legacy BD players. The only solution would be to take advantage of larger BD storage media and issue discs with dual data streams for video (double sided or dual layer if you will).

THE TECHNOLOGY is slowly catching up with the reality. None of the equipment currently made are upto the specifications. Each one does a slight change and calls it better than the next manufacturer. That is all. They ALL are still working with the Research and Development departments, but in one year, they can only do so much and experiment with their knowledge in theory, so they close the shop, switch off the lights, and roll up the sidewalks and call it quits. Then make the next years product. Make a whole lot of money with it and when they return again, they start from where they left off.. then make the next years model. Simple as that.

Just to test what ever that they have put out in the market, they make a TEST CD/DVD and ask you to tune up your TV and see if it is the same as they set up in their Plant. But in the plant they only check one in every so many thousands. So, you will have to do yours or pay some one to do it for you, for a small price. That adds to the cost. So, it is cheaper to buy the cd and fool around with your TV once or twice to get the hang of the colours and how to get them all back as set in the factory. Also some remotes are built with a button that will reset to the factory settings too. So, go and ask the salesman how it can be done with the remote, without sweating or losing your sleep over it.

I hope you got the hang of it now.

FH.