This tool can be used to perform one of eight 3x3 emboss filters on a raster image. Like the sobel_filter and prewitt_filter, the emboss_filter is often applied in edge-detection applications. While these other two common edge-detection filters approximate the slope magnitude of the local neighbourhood surrounding each grid cell, the emboss_filter can be used to estimate the directional slope. The kernel weights for each of the eight available filters are as follows:

North (`n`)

| . | . | .
0 | -1 | 0
0 | 0 | 0
0 | 1 | 0

Northeast (`ne`)

| . | . | .
0 | 0 | -1
0 | 0 | 0
-1 | 0 | 0

East (`e`)

| . | . | .
0 | 0 | 0
1 | 0 | -1
0 | 0 | 0

Southeast (`se`)

| . | . | .
1 | 0 | 0
0 | 0 | 0
0 | 0 | -1

South (`s`)

| . | . | .
0 | 1 | 0
0 | 0 | 0
0 | -1 | 0

Southwest (`sw`)

| . | . | .
0 | 0 | 1
0 | 0 | 0
-1 | 0 | 0

West (`w`)

| . | . | .
0 | 0 | 0
-1 | 0 | 1
0 | 0 | 0

Northwest (`nw`)

| . | . | .
-1 | 0 | 0
0 | 0 | 0
0 | 0 | 1

The user must specify the `direction`, options include 'n', 's', 'e', 'w', 'ne', 'se', 'nw', 'sw'. The user may also optionally clip the output image distribution tails by a specified amount (e.g. 1%).

## See Also

sobel_filter, prewitt_filter

## Function Signature

`def emboss_filter(self, raster: Raster, direction: str = "n", clip_amount: float = 0.0) -> Raster: ...`

## Project Links

WbW Homepage User Manual Support WbW