GeometricMedian

获得 Image Analyst 许可后可用。

摘要

计算多波段影像时间序列中像素的几何中值。

说明

有关此函数工作原理的详细信息,请参阅几何中值函数。

栅格对象所引用的栅格数据集是临时性的。 要将其设置为永久,可以调用栅格对象的 save 方法。

语法

GeometricMedian (rasters, epsilon, {max_iteration}, {extent_type}, {cellsize_type})
参数说明数据类型
rasters
[rasters,...]

The input multiband rasters.

List
epsilon

The convergence value between two consecutive iterations. When epsilon is less than or equal to the specified value, the iteration will stop, and the result of the last iteration will be used.

(默认值为 0.001)

Double
max_iteration

The maximum number of iterations to complete. The computation will end once this value is reached, regardless of the epsilon setting.

(默认值为 10)

Integer
extent_type

Specifies the processing extent for the output raster.

  • FirstOfUse the extent of the first input raster to determine the processing extent.
  • IntersectionOfUse the extent of the overlapping pixels to determine the processing extent. This is the default.
  • UnionOfUse the extent of all the rasters to determine the processing extent.
  • LastOfUse the extent of the last input raster to determine the processing extent.

(默认值为 IntersectionOf)

String
cellsize_type

Specifies the cell size to use in the output raster.

  • FirstOfUse the first cell size of the input rasters. This is the default.
  • MinOfUse the smallest cell size of all the input rasters.
  • MaxOfUse the largest cell size of all the input rasters. This is the default.
  • MeanOfUse the mean cell size of all the input rasters.
  • LastOfUse the last cell size of the input rasters.

(默认值为 MaxOf)

String
返回值
数据类型说明
Raster

输出栅格对象。

代码示例

GeometricMedian 示例

此示例计算 Landsat 影像集合中的几何中值。

# Import system modules
import arcpy
from arcpy.ia import *

# Check out the ArcGIS Image Analyst extension license
arcpy.CheckOutExtension("ImageAnalyst")

# Construct a collection from a mosaic dataset
rc = RasterCollection(r'C:\data.gdb\time_series_landsat_images')

#Execute
geomedian = arcpy.ia.GeometricMedian(rc, {"epsilon": 0.001, "max_iteration": 5, "extent_type":"UnionOf", "CellsizeType": "FirstOf"})

# Save the output
geomedian.save("C:/arcpyExamples/outputs/geomedian_raster.crf")