Filter for reducing a noise component of a chrominance signal and

Abstract

Luminance data Y(1) (i=1,2, - - - ,n, - - - ) are input one by one to a detecting unit, and luminance correlation information R(i-1,i) denoting a luminance correlation or a luminance non-correlation between the luminance data Y(i) and Y(i-1) are generated. Four pieces of luminance correlation information R(n-1,n) to R(n+2,n+3) are stored in a filter controlling unit. Also, chrominance data C(i) are input one by one to a starting-stage chrominance data generating unit, and starting-stage chrominance data C1(n+2) is generated from the chrominance data C(n+1), C(n+2) and C(n+3) according to the luminance correlation information R(n+1,n+2) and R(n+2,n+3). other starting-stage chrominance data C1(n) and C(n+1) are generated in advance in the same manner. Second-stage chrominance data C2(n+1) is generated from the starting-stage chrominance data C(n), C(n+1) and C(n+2) in a second-stage chrominance data generating unit according to the luminance correlation information R(n,n+1) and R(n+1,n+2). Also, other second-stage chrominance data C2(n-1) and C2(n) are generated in advance in the same manner. Smoothed chrominance data C3(n) is generated from the second-stage chrominance data C(n-1), C(n) and C(n+1) in a final-stage chrominance data generating unit according to the luminance correlation information R(n-1,n) and R(n,n+1). Therefore, each of smoothed chrominance data C3(i) can be generated with a limited number of memories at a high speed.