The module opalsSurface contains modules for the derivation of surface models based on different interpolation techniques (Constrained Delaunay Triangulation, Moving Least Squares, Inverse Distance Mapping, Linear Prediction/Kriging ... ) and different data structures (TIN, grid, hybrid grid incl. structure information like breaklines ...). Furthermore, modules for visualization, simplification and analysis of terrain and surface models are included.

Scripts and Modules of Package opalsSurface
Python Scripts	Description
utilsImageOverlay.py	Script to combine a height coloring with a hill shading.
Modules	Description
Algebra	Provides a generic raster algebra calculator featuring mathematical, statistical and conditional operators.
Bounds	Derives and stores the 2D boundary polygon of a region covered by the point data of an ODM or the valid pixels of a raster.
Cell	Calculates statistical features of user defined attributes and stores them as raster models or rasterized point clouds.
Colorize
DSM	Calculates a land cover dependent DSM raster model based on the approach of Hollaus et. al. (2010).
DTM	Calculates a high quality Digital Terrain Model in hybrid grid structure (i.e. regular grid + structure lines).
Diff	Calculates a difference grid model based on either two grids or a one grid and a horizontal reference plane.
DtmAccuracy
Export	Exports vector data stored in an OPALS data manager (ODM) in various data formats.
FillGaps	Detects gaps (i.e. void pixels) in raster models and provides several interpolation methods to close them.
Grid	Derives a 2.5D digital elevation models (DEM) in regular grid structure using simple interpolation techniques.
GridFeature	Derives feature models (slope, curvature, roughness, etc.) from grid models based on the local grid neighbourhood defined by a kernel.
Histo	Derives histograms and descriptive statistics (min, max, mean, r.m.s, etc.) for ODM or grid/raster data sets and stores the results graphically (SVG) and numerically (XML).
Import	Loads vector and raster data into an ODM for subsequent use in modules dealing with point cloud and line related data.
Info	Extracts and reports header information of a vector or raster file (ODM, GDAL).
Isolines	Derives contour lines (isolines) from grid models and stores them as a vector dataset.
Openness	Provides a raster map of local viewsheds (i.e. openness) based on a DTM grid model.
Rasterize	Performs vector-to-raster conversion for all types of simple feature geometries (points, lines, polygons).
Section	Extracts sections of user defined width/length along a specified reference axis from a point cloud (ODM).
Segmentation	Provides methods for point cloud segmentation based on local homogeneity using either a generic region growing approach or an adapted region growing for plane extraction.
Shade	Derives shaded relief raster maps (geo-coded hill shading) of DEM grids.
Simplify	Analyses a regular or hybrid grid model and generates an approximating TIN surface based on a coarse-to-fine approach.
TIN	Creates a TIN surface from ODM vector data based on a 2D constrained Delaunay triangulation.
TerrainFilter	Classifies a 3D point cloud (ODM) into terrain and off-terrain points.
TerrainMask	Identifies open terrain parts of a DSM input raster using the volume based approach by Piltz et al. (2016).
Translate	Performs format conversion for vector data files with additional read support of GDAL rasters.
Vectorize	Performs raster-to-vector conversion and exports polyline geometries.
View	Provides an interactive 3d viewer for points (including arbitrary attributes) and lines.
ZColor	Derives color coded visualizations of grid models and stores them as geo-coded raster images.