§4.8.3高斯低通滤波器(Gaussian Lowpass Filters) Example 2:Gaussian lowpass filtering -D2(u,v) H(u,v)=e 202 Historically,certain computer Historically,certain computer programs were written using programs were written using only two digits rather than only two digits rather than four to define the applicable four to define the applicable year.Accordingly,the year.Accordingly,the company's software may company's software may recognize a date using "00" recognize a date using "00" as 1900 rather than the year as 1900 rather than the year 2000. 2000. ea  Example 2: Gaussian lowpass filtering §4.8.3 高斯低通滤波器 (Gaussian Lowpass Filters) 𝑯(𝒖, 𝒗ሻ = 𝒆 −𝑫 ൯ 𝟐(𝒖,𝒗 𝟐𝝈𝟐