How can I calculate gray levels?

Black and white TV broadcasts occupied a bandwidth of the image signal of approximately 4.5MHz (without considering the vestigial part of the broadcast or the audio carriers). Taking this data into account, you are asked to calculate the equivalent of the number of gray levels that each pixel on the screen could have (equiprobable at all pixels) for an SNR of 30, 20, 10 and 0dB. In which case do you consider that the usual expression “seen with rain” would apply. Can you contrast the data obtained with a reference? Can you do some testing with an image in Matlab?

[Constantino Carlos Reyes-Aldasoro]

This seems like a homework exercise.

I suggest that you try and come back with some specific questions, if you get errors or have problems.