Patent ID: 8284315
Filing Date: 2012-10-09
Classification: H04N

Abstract:
1. A PAL signal demodulating apparatus which demodulates a composite signal of a PAL (phase alternating line) system, comprising: a frame carrier color signal extracting unit to extract a carrier color signal for a frame (m) of interest; a 3D color phase distortion correcting color signal acquiring unit to generate a 3D color phase distortion correcting color signal for the frame (m) of interest using one or both of a frame (m−1) preceding the frame (m) of interest and a frame (m+1) following the frame (m) of interest; a carrier chrominance signal extracting unit to take the addition/subtraction of the 3D color phase distortion correcting color signal and the carrier color signal extracted by the frame carrier color signal extracting unit, thereby extracting carrier chrominance signals for the frame (m) of interest; a BPF processing unit to perform band pass filtering on the composite signal to pass a chroma band, thereby producing a BPF output signal, the 3D color phase distortion correcting color signal acquiring unit configured to obtain one of the BPF output signals for the frame (m−1) and for the frame (m+1), or an average of an inverted signal of the BPF output signal for the frame (m+1) and the BPF output signal for the frame (m−1), as the 3D color phase distortion correcting color signal for the frame (m) of interest; a motion detecting unit to detect motion from the composite signal; a 2D color phase distortion correcting color signal acquiring unit to obtain one of the BPF output signals for a line (n−1) preceding a line (n) of interest and for a line (n+1) following the line (n) of interest, or an average of an inverted signal of the BPF output signal for the line (n+1) and the BPF output signal for the line (n−1), as a 2D color phase distortion correcting color signal for the line (n) of interest; an average color phase distortion correcting color signal acquiring unit to take a weighted average of the 3D color phase distortion correcting color signal for the line (n) of interest in the frame (m) of interest and the 2D color phase distortion correcting color signal for the line (n) of interest with such weights that the larger the motion detected by the motion detecting unit is, the larger the weight of the 2D color phase distortion correcting color signal, thereby producing an average color phase distortion correcting color signal for the line (n) of interest; and a line carrier color signal extracting unit to extract a carrier color signal for the line (n) of interest, the carrier chrominance signal extracting unit configured to take the addition/subtraction of the carrier color signal for the line (n) of interest extracted by the line carrier color signal extracting unit and the average color phase distortion correcting color signal, thereby extracting carrier chrominance signals for the line (n) of interest.