matlab中的conv2卷积运算的三种形式

thinkfunny

9 z$ {3 Y% W# A  K  Z$ k# wmatlab中的conv2是用于对二维数据进行卷积运算，有三个参数可供选择，下面是help content of conv2
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% Q' q. P, B+ ?conv2 Two dimensional convolution.

! q) R  L$ P' @5 h) T+ k    C = conv2(A, B) peRForms the 2-D convolution of matrices A and B.
- f- c: s" M% r    If [ma,na] = size(A), [mb,nb] = size(B), and [mc,nc] = size(C), then
    mc = max([ma+mb-1,ma,mb]) and nc = max([na+nb-1,na,nb]).
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! M' u9 z- F' a' m    C = conv2(H1, H2, A) first convolves each column of A with the vector
    H1 and then convolves each row of the result with the vector H2.  If
    n1 = length(H1), n2 = length(H2), and [mc,nc] = size(C) then
% M- W7 _- P- t/ D    mc = max([ma+n1-1,ma,n1]) and nc = max([na+n2-1,na,n2]).
. x9 ^7 O8 ?% f0 O" ~    conv2(H1, H2, A) is equivalent to conv2(H1(：)*H2(：).', A) up to
3 P! \' |5 m9 E5 Y( m8 e    round-off.

8 K% x* M; A  c  \    C = conv2(..., SHAPE) returns a subsection of the 2-D
# z" ]2 B; A6 f, G  x) E! J- G% Y    convolution with size specified by SHAPE:
      'full'  - (default) returns the full 2-D convolution,
) a& O# _' k5 K      'same'  - returns the central part of the convolution
                that is the same size as A.
      'valid' - returns only those parts of the convolution
- @. \6 \! J0 F" _) [  B6 |- y7 f                that are computed without the zero-padded edges.
                size(C) = max([ma-max(0,mb-1),na-max(0,nb-1)],0).
  r% m$ g1 j, W* l5 m& z4 ?# ?

; @( `8 L4 c/ q0 ^0 w. S关于full, same以及valid三种参数的区别，如下面的实例所示：

full


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same

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4 C( `6 l, K( U2 c( o- D: W( ovalid

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yin123

三种形式的matlab中的conv2卷积运算