Picture feature extraction system and picture quality evaluation system

摘要

This invention is intended to reduce a line rate of a monitoring line necessary for transmission of a picture feature without complicating a system. A video signal x_i (n₀, n₁) of each block is subjected to spread spectrum by multiplying the video signal x_i(n₀, n₁) by a PN sequences S_PN1 (n₀, n₁) (in a step S1). The resultant video signal is orthogonally transformed by DFT, DCT, WHT, or the like (in a step S2). An amplitude component A_i=|X_i(S_E0, S_E1)| of an arbitrary component (S_E0, S_E1) in a coefficient X_i(S₀, S₁) obtained by the steps S1 and S2 is extracted (in a step S3), and the extracted amplitude component is quantized with a step size M (in a step S4). The picture feature F[i] is given as a residue obtained under a modulus N_m of a quantized typical value obtained by the quantization (in the step S4) (in a step S5).