Spatial Filter

• Instead of “画素” (pixels), it’s more like “画素周辺領域” (neighborhood of pixels).

• The equation for a 線形 (linear) filter:

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  • h(m,n) represents the coefficients of the filter array.
  • f() represents the original image.
  • W is half the width of the filter.

• Anything that doesn’t fit the above equation is a non-linear filter.

• There are many specific examples written in Contour Detection.

  • The contour detection one is essentially 微分 (differentiation).
    • The difference is that it’s not lim h->0, but just 1px.

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  • When applying multiple filters, they can be combined into one. (see the diagram)
    • Treat the filters as images and apply a second filter to each cell of the filter.