ENVIRegridRasterSeriesByUnion Task

RegridRasterSeriesByUnion Task

This task regrids a series of rasters to a common spatial grid, using the geometric union of the source rasters. All of the source rasters must be in the same coordinate system. The pixel size of the output series is determined by the first raster in the series.

Example

This example builds a raster series from a collection of Landsat MSS, TM, and -8 images. They are all georeferenced to the same coordinate system, but their sizes and resolution are different. The example uses the geometric union of the source rasters as the basis for reprojecting the other rasters in the series.

This example uses sample images files are available from our ENVI Tutorials web page. Click the Landsat Case Studies link to download the .zip file to your machine, then unzip the files. The files you will use in this example are located in the TimeSeries folder of the download. Update the file references in the example with the correct locations.

; Start the application

e = ENVI()

; Select input rasters

Files = FILE_SEARCH('C:\Data', 'LasVegas*.dat')

; Get the build raster series task from the catalog of ENVITasks

Task = ENVITask('BuildRasterSeries')

numRasters = N_Elements(Files)

rasters = ObjArr(numRasters)

FOR i=0, (numRasters-1) DO $

  rasters[i] = e.OpenRaster(Files[i])

; Define inputs

Task.INPUT_RASTERS = rasters

; Run the task

Task.Execute

Series = Task.OUTPUT_RASTERSERIES

; Get the task from the catalog of ENVITasks

RegridTask = ENVITask('RegridRasterSeriesByUnion')

; Define inputs

RegridTask.INPUT_RASTERSERIES = Series

; Run the task

RegridTask.Execute

; Get the collection of data objects currently available in the Data Manager

DataColl = e.Data

; Add the output to the Data Manager

DataColl.Add, RegridTask.OUTPUT_RASTERSERIES

; Display the result

View = e.GetView()

Layer = View.CreateLayer(RegridTask.OUTPUT_RASTERSERIES)

Syntax

Result = ENVITask('RegridRasterSeriesByUnion')

Input parameters (Set, Get): INPUT_RASTERSERIES, OUTPUT_RASTERSERIES_URI, RESAMPLING

Output parameters (Get only): OUTPUT_RASTERSERIES

Parameters marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Parameters marked as "Get" are those whose values you can retrieve but not set.

Input Parameters

INPUT_RASTERSERIES (required)

Specify a raster series to reproject.

OUTPUT_RASTERSERIES_URI (optional)

Specify a string with the fully-qualified path and filename for OUTPUT_RASTERSERIES.

RESAMPLING (optional)

Specify the resampling method to use when creating the spatial grid:

Nearest Neighbor (default): Uses the nearest pixel without any interpolation.
Bilinear: Performs a linear interpolation using four pixels to resample.
Cubic Convolution: Uses 16 pixels to approximate the sinc function using cubic polynomials to resample the image.