The difference of averaging filters [1] is another type of a band-pass filter. The filtered image is obtained by subtracting images filtered with two averaging filters having different user-specified kernel sizes,
Similar to the difference-of-Gaussians filter,
the size of the kernel
has to be larger than
.
The threshold value can be specified by users as an expression combining mathematical functions and operators with variables based on the current raw or filtered image. Variables provided by this filter are:
| DoB.I | current raw input image |
|---|---|
| DoB.F | corresponding filtered image |
| DoB.B1 | result of filtering only with |
| DoB.B2 | result of filtering only with |