• 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:

  • image

    • 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.
  • image

    • 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.