Tool NameMultilevel B-Spline from Grid Points
Tool ID5
Library IDgrid_spline
Version1.0
Author(s)O.Conrad (c) 2006

Description

Multilevel B-spline algorithm for spatial interpolation of scattered data as proposed by Lee, Wolberg and Shin (1997). The algorithm makes use of a coarse-to-fine hierarchy of control lattices to generate a sequence of bicubic B-spline functions, whose sum approaches the desired interpolation function. Large performance gains are realized by using B-spline refinement to reduce the sum of these functions into one equivalent B-spline function.

The 'Maximum Level' determines the maximum size of the final B-spline matrix and increases exponential with each level. Where level=10 requires about 1mb level=12 needs about 16mb and level=14 about 256mb(!) of additional memory.

References

Lee, S., Wolberg, G., Shin, S.Y. (1997): Scattered Data Interpolation with Multilevel B-Splines. IEEE Transactions On Visualisation And Computer Graphics, Vol.3, No.3., p.228-244. doi:10.1109/2945.620490

Parameters

NameTypeIdentifierDescriptionConstraints
Input
Gridgrid, inputGRID
Target Systemgrid, input, optionalTARGET_TEMPLATEuse this grid's system for output grids
Output
Target Gridgrid, outputTARGET_OUT_GRID
Options
Target Grid SystemchoiceTARGET_DEFINITIONAvailable Choices:
[0] user defined
[1] grid or grid system
Default: 0
Cellsizefloating point numberTARGET_USER_SIZEMinimum: 0.000000
Default: 1.000000
Westfloating point numberTARGET_USER_XMINDefault: 0.000000
Eastfloating point numberTARGET_USER_XMAXDefault: 100.000000
Southfloating point numberTARGET_USER_YMINDefault: 0.000000
Northfloating point numberTARGET_USER_YMAXDefault: 100.000000
Columnsinteger numberTARGET_USER_COLSNumber of cells in East-West direction.Minimum: 1
Default: 101
Rowsinteger numberTARGET_USER_ROWSNumber of cells in North-South direction.Minimum: 1
Default: 101
RoundingbooleanTARGET_USER_FLATRound bounding coordinates to multiples of cell size. Ignored if cell size has decimal places.Default: 1
FitchoiceTARGET_USER_FITSAvailable Choices:
[0] nodes
[1] cells
Default: 0
Data TypechoiceDATATYPEAvailable Choices:
[0] same as input grid
[1] 4 byte floating point number
Default: 0
RefinementchoiceMETHODAvailable Choices:
[0] no
[1] yes
Default: 0
Threshold Errorfloating point numberEPSILONMinimum: 0.000000
Default: 0.000100
Maximum Levelinteger numberLEVEL_MAXMinimum: 1
Maximum: 14
Default: 11