Television-The Scanning Process

This is a descriptive study of the scanning process in television. It is analyzed in terms of a two-dimensional Fourier series of terms, which are correlated to the frequency components of the transmitted electrical signal. The impairment caused to the detail in the picture by the scanning process is shown to consist of two parts: (a) a blurring of the original image, and (b) the introduction of spurious patterns not in the original picture. A discussion is given of how these influence the reproduction of detail in the vertical and horizontal directions, and their relative importance in impairing the picture. A brief discussion is also given of impairments to the over-all picture caused by the scanning process, chiefly from the intermittent nature of the process.