Karika QGIS 3 Processing Plugin Help

1 Introduction

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.

demo.jpg

2 Parameters

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

gui.png

3 The C extension module

The core of the algorithm is implemented in C and compiled as a shared library. Binaries for Windows, Mac, and Linux are shipped with the plugin. If none of these fit your platform, you need to compile the binaries by yourself.

See the lib/src folder for example Makefile projects. E.g., on Linux you would compile it using

make -f Makefile.Linux

while on Windows you would run

make_win_msvc.bat

if you are using the MS Visual C compiler, or, if using LLVM

make_win_clang.bat

The compiled module must reside in the lib folder in order to be found by the processing plugin.