RasterHistogram Task
This task computes a histogram for a raster.
Example
; 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('RasterHistogram')
; Define inputs
Task.INPUT_RASTER = Raster
; Run the task
Task.Execute
; Display histogram results in a plot window
nbands = Task.INPUT_RASTER.nBands
color = [[!color.red],[!color.green],[!color.blue],[!color.violet]]
for band=0, nbands-1 do $
p = plot(findgen(task.Output_nBins[band], Start=task.output_min[band], $
increment=task.Output_BinSize[band]), (task.output_counts[band]), $
/hist,buffer=buffer, /overplot, color=color[*,band], ytickformat='(g0)', $
thick=2, clip=0)
Syntax
Result = ENVITask('RasterHistogram')
Input properties (Set, Get): INPUT_BINSIZE, INPUT_MAX, INPUT_MIN, INPUT_NBINS, INPUT_RASTER
Output properties (Get only): OUTPUT_BINSIZE, OUTPUT_COUNTS, OUTPUT_MAX, OUTPUT_MIN, OUTPUT_NBINS
Properties marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Properties marked as "Get" are those whose values you can retrieve but not set.
Methods
This task inherits the following methods from ENVITask:
Properties
This task inherits the following properties from ENVITask:
This task also contains the following properties:
INPUT_BINSIZE (optional)
Specify a value for the bin size, to manage the resolution of the histogram. INPUT_BINSIZE is mutually exclusive from INPUT_NBINS.
INPUT_MAX (optional)
Specify the maximum value of the histogram for each band. Set to a scalar value that applies to all bands, or set to an array of values, one per band.
INPUT_MIN (optional)
Specify the minimum value of the histogram for each band. Set to a scalar value that applies to all bands, or set to an array of values, one per band.
INPUT_NBINS (optional)
Specify a value for the number of bins. INPUT_NBINS is mutually exclusive from INPUT_BINSIZE. If you do not specify either of these properties, a default value of 256 bins will be used for all bands.
INPUT_RASTER (required)
Specify a raster from which to generate histogram statistics.
OUTPUT_BINSIZE
This is the bin size of the histogram for each band.
OUTPUT_COUNTS
This is the pixel count of the histogram for each band.
OUTPUT_MAX
This is the maximum value of the histogram for each band.
OUTPUT_MIN
This is the minimum value of the histogram for each band.
OUTPUT_NBINS
This is the number of bins the histogram was limited to for each band.
Version History
|
ENVI 5.3 |
Introduced |
API Version
4.2