§4.9.4频率域的拉普拉斯算子 Hu,D)=-4π2[(u-22+(w-921 72f(x,y)=S-1{H(u,v)F(u,)} g(x,y)=f(x,y)+cV2f(x,y) g(x,y)=f(x,y)-72f(x,y) V g(x,y)=3-1{F(u,v)-H(u,v)F(u,v)} =3-1{F(u,v)[1-Hu,)]} =S-1{F(u,)[1+4π2D2(u,v)]}𝛻 2𝑓 𝑥, 𝑦 = ℑ −1 𝐻 𝑢, 𝑣 𝐹(𝑢, 𝑣) 𝑔 𝑥, 𝑦 = 𝑓 𝑥, 𝑦 + 𝑐𝛻 2𝑓 𝑥, 𝑦 𝑔 𝑥, 𝑦 = ℑ −1 𝐹 𝑢, 𝑣 − 𝐻 𝑢, 𝑣 𝐹(𝑢, 𝑣) = ℑ −1 𝐹 𝑢, 𝑣 [1 − 𝐻 𝑢, 𝑣 ] = ℑ −1 𝐹 𝑢, 𝑣 [1 + 4𝜋 2𝐷 2 𝑢, 𝑣 ] §4.9.4 频率域的拉普拉斯算子 𝐻 𝑢, 𝑣 = −4𝜋 2 [(𝑢 − 𝑃 2 ) 2+(𝑣 − 𝑄 2 ) 2 ] 𝑢 𝑣 c = -1 𝑔 𝑥, 𝑦 = 𝑓 𝑥, 𝑦 − 𝛻 2𝑓 𝑥, 𝑦