ConvolutionReplace each pixel by a linear combination of its neighbors (and possibly includes itself)박스로 적용하는 게 아니라 픽셀별로 적용 Examplesblur (111111111)\begin{pmatrix} 1 & 1 & 1 \\ 1 & 1 & 1 \\ 1 & 1 & 1 \\ \end{pmatrix}111111111