G2S: The GeoStatistical Server

A free and flexible multiple point (geo)statistics framework including state-of-the-art algorithms: QuickSampling and Narrow Distribution Selection

Parameters for NDS

Flag Description Mandatory
-ti Training images (one or more images). If multivariate, the last dimension should match the number of variables and the size of -dt. NaN values in the training image are ignored.
-di Destination image (simulation grid). NaN values are simulated and non-NaN values are treated as conditioning data.
-dt Data type. 0 for continuous and 1 for categorical. This also defines the number of variables.
-k Number of best candidates used to evaluate the narrowness.
-ki Weighting kernel. This defines the search neighborhood and can also be used to normalize variables. If omitted, NDS generates a default kernel internally.  
-nw Narrowness range. 0 corresponds to max-min, 1 approaches the median, default is 0.5 (interquartile range).  
-nwv Number of variables used to compute the narrowness, counted from the end of the variable list. Default: 1.  
-cs Chunk size: number of pixels simulated together at each iteration. Default: 1.  
-uds Update radius: number of nearby pixels updated around each simulated pixel. Default: 10.  
-mp Partial simulation ratio. 0 means empty and 1 means a full simulation. Default: 1.  
-s Random seed.  
-j Parallel execution settings. Use -j, N1, N2, N3, where all three values are optional but N3 requires N2, and N2 requires N1. Decimal values in ]0,1[ represent a fraction of the available logical cores.  
-wd Use the kernel distance.  
-ed Use the Euclidean distance. This is the default.  
-md Use the Manhattan distance.  
-W_GPU Use an integrated GPU if available.  
-nV No Verbatim mode (experimental).  

Examples

NDS is primarily intended for spectrally guided simulation and colorization tasks. The active implementation is controlled by the narrowness parameters -nw and -nwv, together with the chunking and update controls -cs, -uds, and -mp.

Publication

Gravey, M., Rasera, L. G., & Mariethoz, G. (2019). Analogue-based colorization of remote sensing images using textural information. ISPRS Journal of Photogrammetry and Remote Sensing, 147, 242–254. https://doi.org/10.1016/j.isprsjprs.2018.11.003