In a later lecture, we talked about the inner product of two functions. Hopefully, you can see the that response of a sensor is the inner product of the input signal and the sensor's response function.
In this sense, the response of a sensor provides a measure of how much the signal "lines up" with the sensor's response function. For example, in this context of this lecture, the response function of the L-cone is much stronger for long wavelength light (think: redder light). Therefore, we loosely often say that the L-cone measures how much red light there is in the scene. (Although that technically is not true, in reality it responses to a wide range of frequencies, it is just most sensitive to the longer wavelength.)
Jump ahead to slide 22 and take a look at the response curves for the three types of cone photoreceptor cells in the eye.
In a later lecture, we talked about the inner product of two functions. Hopefully, you can see the that response of a sensor is the inner product of the input signal and the sensor's response function.
In this sense, the response of a sensor provides a measure of how much the signal "lines up" with the sensor's response function. For example, in this context of this lecture, the response function of the L-cone is much stronger for long wavelength light (think: redder light). Therefore, we loosely often say that the L-cone measures how much red light there is in the scene. (Although that technically is not true, in reality it responses to a wide range of frequencies, it is just most sensitive to the longer wavelength.)
Jump ahead to slide 22 and take a look at the response curves for the three types of cone photoreceptor cells in the eye.