Models of television YUV, YQI

After the first show of black and white television (1926), there has been emerged the strong impulse to construct systems of color television. As we have mentioned, the first public demonstration of color television took place in 1929. But the first general television for color reception took place only in 1956 in USA. This date is therefore assumed that it is the date of starting of the first transmitter for the public color television.
Television, which was just sprang out, has realized the reasoning in the construction of the models of area colors. Practically, there are existing two models very similar to each other. Differences result from different technical decisions of the independent from one another constructors and designers of television signal. Practically, two kinds of the models of area colors for television signal have been become widespread in the world.

Television is based on model YUV in Europe, and there is yet a division within this model, in consideration of the manner of coding of the components of model. This manner of coding is called by the systems of names: PAL and SECAM.

Symbolic letters in the name of model have definitions only within these models. For example, you should not join the symbol Y with the same symbols in other models.

There is spread on American continent (USA, Canada ) and in Southeastern Asia (Japan) the system of transmitting of color television called NTSC. The model of description of colors in this system is called YQI.

In all these models Luminance is the same. This fact should allow it for each televisor to have the possibility of picture reproducing, at least black and white. In fact, however you can meet situations that it is not so. It results from the fact of dissimilarity of manner of final construction of television signal for emitting by transmitter. For example, in France there is existing french Secam which differs in that, among other things, that the luminance is sent as a denied value. And such detail makes already possible for reception of pictures by an unadapted televisor.

The component Y called luminance, practically, at a given moment for the entirely multicolored picture fixes a place, somewhere between a minimum and a maximum. Fixing R, G and B, and individual use of them lowers or increases individually the emission for proper three colors in kinescope. We desire to call your attention here, that the component Y corresponds more or less the light Lightness defined by CIE organization, but according to values is different from definitions coming from this organization. For practicians this is the black and white content of the entirely colored picture.