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<SUB>i </SUB>(n<SUB>0</SUB>, n<SUB>1</SUB>) of each block is subjected to spread spectrum by multiplying the video signal x<SUB>i</SUB>(n<SUB>0</SUB>, n<SUB>1</SUB>) by a PN sequences S<SUB>PN1 </SUB>(n<SUB>0</SUB>, n<SUB>1</SUB>) (in a step S 1 ). The resultant video signal is orthogonally transformed by DFT, DCT, WHT, or the like (in a step S 2 ). An amplitude component A<SUB>i</SUB>=|X<SUB>i</SUB>(S<SUB>E0</SUB>, S<SUB>E1</SUB>)| of an arbitrary component (S<SUB>E0</SUB>, S<SUB>E1</SUB>) in a coefficient X<SUB>i</SUB>(S<SUB>0</SUB>, S<SUB>1</SUB>) obtained by the steps S 1 and S 2 is extracted (in a step S 3 ), and the extracted amplitude component is quantized with a step size M (in a step S 4 ). The picture feature F[i] is given as a residue obtained under a modulus N<SUB>m </SUB>of a quantized typical value obtained by the quantization (in the step S 4 ) (in a step S 5 ).
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