Abstract: Method and apparatus for generating amplitudes of picture points in a line-by-line picture signal for a display device from subpicture information encoded as coefficients of a Hadamard transform. Amplitudes of the picture points in a line are determined by generating selected elements of a basis vector associated with each coefficient in a Hadamard matrix and, for each element, forming a product of the coefficient and a factor determined according to the value of the element. Each element and the product determined therefrom relate to a picture point. All the products for each picture point are added to give the amplitude for that point.