Digital apparatus to compose a series of PAL or PAL-M video pictures from a single field

摘要

1. Digital device for the reconstitution of a sequence of PAL or PAL-M video images from a single frame stored in a memory, comprising : - means (2, 3) for sampling and digitalizing a composite video signal ; - means (16 and 29) for storing and restituting the values of the composite video signal corresponding to a frame ; - means (17) for determining a luminance value and a chrominance value for each value of restituted composite video signal ; - means (23) for the reconstitution of the luminance values corresponding to a line of a frame to be reconstituted, from the luminance values of the corresponding line or the two closest lines in the stored frame ; - means for the reconstitution of the chrominance values corresponding to a line of a frame to be reconstituted, from the chrominance values of the corresponding line or the two closest lines in the stored frame, these means comprising : means (36, 11) for inverting one of the components of a PAL or PAL-M chrominance signal and at least one device (18) delaying by one line, in order to provide two chrominance values Cm-1 and Cm corresponding to two corresponding points of two successive lines of the stored frame ; - an adder (27) for supplying a composite video signal by adding the values supplied by the means (23) for the reconstitution of the luminance values with the values supplied by the means for the reconstitution of the chrominance values ; characterized in that the means for the reconstitution of the chrominance values further comprise : - a device (22) for the phase shifting of the values of a chrominance signal, having control inputs controlling a phase shift by + pi/2, or - pi/2 ; - computing means (19, 20, 24, 25, 26) for calculating a reconstituted chrominance value ; - control means (30) controlling the computing means (19, 20, 24, 25, 26) and the phase shifting device (22) as a function of the number of the frame to be reconstituted and as a function of the number of the stored frame.