It is with tremendous pleasure that I announce the release of the latest version of Whitebox Geospatial Analysis Tools, version 3.2.2. It has been several months since the release of the previous version of Whitebox GAT and we have incorporated several significant new features, tools, and bug fixes. The following is a partial list of changes:
- LAS files can now be rendered based on the Classification, Scan Angle, and GPS Time in addition to Elevation and Intensity. This is on top of several other improvements that have been made to the display of LAS file data in Whitebox GAT.
- Added Conditional Evaluation tool (if-then-else statement). I really like this tool and now wonder how it was that I managed to get by without it.
- Added a PickFromList tool, which outputs a raster with the value from a stack
of rasters based on an input position raster.
- Added LowestPosition, HighestPosition, PercentEqualTo, PercentGreaterThan, and PercentLessThan tools for working with raster stacks, i.e. lists of overlapping
- Added a tool to create histograms based on the elevations, intensity, and
scan angles within a LiDAR (LAS) file. It will also output the percentiles of
the distribution, e.g. 95th percentile of elevation.
- Added the AddPointCoordinateToTable tool, which can be used to add the x-y
coordinates of points within a Point type ShapeFile as fields within its attribute table.
- Added a tool to filter the points in a LiDAR (LAS) file based on a threshold
in the absolute scan angle. Currently the output is a shapefile of mass-point shape but eventually we would like to have it write to a new LAS file.
- The Merge Points Files tool was replaced with the more general Merge Shapefiles
tool, which works with any ShapeType.
- Added the FindLowestHighestLocations tool, which will output vector points
corresponding to the lowest and highest points in a raster. This has already come in handy several times.
- Added ExtractRasterValuesAtPoints tool for extracting the cell values of each
image in a raster stack corresponding to a set of vector points. Values are
placed within the vector attribute table.
- Added DeleteSmallLakesAndExtendRivers tool, which can be used to remove small lakes (polygons) in a vector drainage network and to extend the associated river
network (intersecting polylines) into the interior of the lake. I created this tool in response to an interesting question asked over on the GIS Stack Exchange.
- Added a Long Profile From Point tool, which can generate one or more longitudinal
profiles for the flowpaths issuing from a set of vector points.
- Modified the Mosaic With Feathering tool to handle RGB images in addition to
continuous scale rasters. At the moment, this only works for the nearest-
neighbour mode. I’m not sure why I didn’t do this earlier.
- Added Image Stack Profile tool to create a line graphs for a set of vector points
through an image stack, such as multi-spectral satellite image data. This can be handy for visualizing the spectral signatures of individual pixels.
- Added a Simple Region Grow tool that will perform a very simple region grow
segmentation of pixels in an image stack based on a specified threshold. I’d like to continue development in this area and eventually include a full object-based image segmentation.
- Added parallel implementations of the D8 flow pointer and accumulation algorithms. At the moment this is really an experimental tool that is not intended for widespread use but there is more to come, including parallel versions of all the flow accumulation algorithms.
- Fixed a bug in the Hillslopes tool.
- I’ve added a whole suite of tools to the Elevation Residuals toolbox for
performing multi-scaled topographic position analysis. This includes modified
tools for calculating difference and deviation from mean elevations using an
integral image approach that is extremely computationally efficient, even with
large search windows. It also includes the Local Topographic Position Scale
Signature and the Maximum Elevation Deviation tools. Combined with the
‘customRGBScript.groovy’ script, these functions allow for the creation of
some spectacular multi-scale topographic position visualizations. See this link
And like a proud father, I can’t resist showing some nice pictures…
One point of note is that Oracle stopped supporting Java on Windows XP some time ago and therefore recent versions of Whitebox GAT no longer function on this platform. It’s time to upgrade!
Please let me know if you have any feedback or questions regarding the new version of Whitebox GAT and I hope you enjoy all the new goodies. As always, best wishes and happy geoprocessing.
UPDATE (April 15, 2015): It would seem that there were some issues with some of the plugin tools written as Groovy scripts that resulted from breaking changes associated with the update from Groovy 2.3 to Groovy 2.4.1. To overcome these issues I regressed the Groovy library linked to by Whitebox GAT to the 2.3 version and now all of the affected tools are working properly. Thank you to the users that alerted me to this issue.