Here I suppose to explain the composite video signal, but the page is under development. Below you can look at some pictures captured from a digital oscilloscope.

		A composite video signal which contains a number of horizontal lines in the captured picture. The lines is separated by composite synchronizations (horizontal blanking intervals) which let you know the end of a line. The part of every line that looks noisy contains the black level of every pixel. To measure the grey scale of a pixel you only have to measure the height of the signal. More information when this page is finnished.
		The same signal as above, but one horizontal line in more detail. As you can see the line is approximately 64us wide and there is 15620 lines per second if you don't considerate the vertical blanking interval below. 15620 lines divide by 50 frames per second give us a picture with the height of 312 pixels.
		The beginning of a vertical blanking interval. In the interlaced video signal it's two different vertical intervals per frame, one for the odd and one for the even frame. That help us to know which frame it is.
		The same signal as above, but now the whole vertical blanking interval. The interval is approximately 1.61ms wide.
		The last picture contains a horizontal line with a couple of pixels that have a high black level (i.e. white pixels). If you capture and draw the whole picture you probably see a bright spot.