This tool performs a conservative smoothing filter on a raster image. A conservative smoothing filter can be used to remove short-range variability in an image, effectively acting to smooth the image. It is particularly useful for eliminating local spikes and reducing the noise in an image.
Arguments
- x
Raster object of class WhiteboxRaster. See
wbw_read_raster()for more details.- filter_size_x
integer, X dimension of the neighbourhood size- filter_size_y
integer, Y dimension of the neighbourhood size
Value
WhiteboxRaster object containing filtered values
Details
The algorithm operates by calculating the minimum and maximum neighbouring values surrounding a grid cell. If the cell at the centre of the kernel is greater than the calculated maximum value, it is replaced with the maximum value in the output image. Similarly, if the cell value at the kernel centre is less than the neighbouring minimum value, the corresponding grid cell in the output image is replaced with the minimum value.
Neighbourhood size, or filter size, is specified in the x and y dimensions
using filter_size_x and filter_size_y These dimensions should
be odd, positive integer values (e.g. 3L, 5L, 7L, 9L, etc.).
References
For more information, see https://www.whiteboxgeo.com/manual/wbw-user-manual/book/tool_help.html#conservative_smoothing_filter
Examples
f <- system.file("extdata/dem.tif", package = "wbw")
wbw_read_raster(f) |>
wbw_conservative_smoothing_filter(filter_size_x = 3L, filter_size_y = 3L)
#> +-----------------------------------------------+
#> | WhiteboxRaster |
#> | dem.tif |
#> |...............................................|
#> | bands : 1 |
#> | dimensions : 726, 800 (nrow, ncol) |
#> | resolution : 5.002392, 5.000243 (x, y) |
#> | EPSG : 2193 (Linear_Meter) |
#> | extent : 1925449 1929446 5582091 5585717 |
#> | min value : 63.808151 |
#> | max value : 360.846832 |
#> +-----------------------------------------------+