Karika QGIS 3 Processing Plugin Help

This processing module implements raster generalization by line integral convolution of the raster values along the surface gradient, as described in the PhD thesis Automatic Swiss style rock depiction.

In the images below, hillshading is used to demonstrate the effect of this method: the original elevation raster is on the left, the generalized raster is on the right.

Cells within a distance of D=⌊integration length/2⌋+1 are regarded as invalid, since the integration may be incomplete due to the missing data beyond the raster boundaries.

Add a buffer margin of size D around your region of interest to ensure the validity all generalized cell values within that region.

The Border mode parameter (see below) lets you choose a way of dealing with the border values.

Input raster

Elevation raster.

Integration length

The main parameter, higher values correspond to increased abstraction of the terrain.

Band number

Number of the raster band, defaulting to 1.

Z factor

Elevation value scale, defaulting to 1. Must be greater than zero.

Border mode

Handling of invalid cells up to a distance of D=⌊integration length/2⌋+1 from the raster boundaries:

• Keep: retain the incomplete values; this is the default
• Crop: remove D columns or rows from each side of the raster; the raster extent and geo transform are modified
• Fill: fill the border with the nodata value of the raster (-32768 if raster has no predefined nodata value)

Output raster

Destination raster. Currently, only the GeoTiff file format is supported.