PixelScaleResampleRaster Task

This task resamples a raster to different dimensions by multiplying the pixel size by a scale factor.

The virtual raster associated with this task is ENVIResampleRaster.

Example

This example opens a 1024 x 1024 pixel raster whose pixel size is 2.8 meters. It multiplies a scale factor of 2.5 to the pixels to produce a raster that is 410 x 410 in size with 7-meter pixels.

; Start the application

e = ENVI()

; Open an input file

File = Filepath('qb_boulder_msi', Subdir=['data'], $

Root_Dir=e.Root_Dir)

Raster = e.OpenRaster(File)

; Get the task from the catalog of ENVITasks

Task = ENVITask('PixelScaleResampleRaster')

; Define inputs

Task.INPUT_RASTER = Raster

Task.PIXEL_SCALE = [2.5, 2.5]

; Run the task

Task.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, Task.OUTPUT_RASTER

; Display the result

View = e.GetView()

Layer = View.CreateLayer(Task.OUTPUT_RASTER)

Syntax

Result = ENVITask('PixelScaleResampleRaster')

Input parameters (Set, Get): INPUT_RASTER, OUTPUT_RASTER_URI, PIXEL_SCALE, RESAMPLING

Output parameters (Get only): OUTPUT_RASTER

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_RASTER (required)

Specify the raster to resample.

OUTPUT_RASTER_URI (optional)

Specify a string with the fully qualified filename and path to export the associated OUTPUT_RASTER.

If you set this parameter to an asterisk symbol (*), the output raster will be virtual and not written to disk.
If you do not specify this parameter, or set it to an exclamation symbol (!), a temporary file will be created.
If you set it to the hash symbol (#), ENVI creates a file in the temporary directory, but this file will not be deleted when ENVI closes.

PIXEL_SCALE (required)

Specify a two-element array of positive values that define how each pixel will be resized. Setting this parameter can result in the resampled raster having slightly different geographic extents than the source raster. Scaled pixels may not exactly cover the same geographic area as the original pixels. The upper-left corners will coincide while the right and bottom edges will be scaled by a sub-pixel amount.

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.