RasterStretchColorizer

Summary

Represents a raster stretch colorizer.

Discussion

The raster stretch colorizer stretches values along a color ramp. The properties behave in a similar manner to the options exposed in the application. For example, changing the StretchType will control a subset of additional parameters that can be modified.

Properties

Property	Explanation	Data Type
band (Read and Write)	An integer that represents a zero-based index matching the order of the bands the way they appear in the Symbology pane. The topmost band is index 0 and the bottommost is n-1.	Integer
colorRamp (Read and Write)	Provides access to the ColorRamp object.	ColorRamp
gamma (Read and Write)	A double that represents the gamma value.	Double
invertColorRamp (Read and Write)	A Boolean that reverses the color ramp's appearance.	Boolean
maxLabel (Read and Write)	A string that represents the raster stretch maximum label that appears in the Contents pane or legend.	String
maxPercent (Read and Write)	A double that represents the percentage of highest values to cut from the source data. This parameter is only applied if the StretchType is set to MinimumMaximum.	Double
minLabel (Read and Write)	A string that represents the raster stretch minimum label that appears in the Contents pane or legend.	String
minPercent (Read and Write)	A double that represents the percentage of lowest values to cut from the source data. This parameter is only applied if the StretchType is set to MinimumMaximum.	Double
standardDeviation (Read and Write)	A double that represents the standard deviation value. This parameter is only applied if the StretchType is set to StandardDeviation.	Double
stretchType (Read and Write)	A string that represents a valid stretching algorithm. The valid values are as follows: Custom—Display values with custom histogram. Esri—Highlight the contrast of moderate values while minimizing the impact of extreme high and low values. HistogramEqualize—Display values with histogram equalize. HistogramSpecification—Display values with histogram specification. MinimumMaximum—Display values between the actual minimum and maximum values. None—Display values between potential minimum and maximum. PercentClip—Cut off percentages of highest and lowest values. StandardDeviation—Display values between a specified number of standard deviations.	String
type (Read Only)	Returns a string that represents the colorizer type.	String

Code sample

RasterStretchColorizer example

The following script first tests whether the layer's symbology supports a colorizer property, then confirms whether the renderer is a RasterStretchColorizer. Next,. it changes the stretchType to PercentClip and sets the appropriate min/max percents. Finally, it changes ColorRamp to a color ramp named Bathymetry #2.

p = arcpy.mp.ArcGISProject('current')
m = p.listMaps('RasterStretch')[0]

for l in m.listLayers():
  if l.isRasterLayer:
    sym = l.symbology
    if hasattr(sym, 'colorizer'):
      if sym.colorizer.type == 'RasterStretchColorizer':

        #Set StretchType = PercentClip
        if l.name == "Photo_SE":
          sym.colorizer.stretchType = "PercentClip"
          sym.colorizer.minPercent = 1.0
          sym.colorizer.maxPercent = 1.0
          cr = p.listColorRamps('Bathymetry #2')[0]
          sym.colorizer.colorRamp = cr
          sym.colorizer.invertColorRamp = True
          sym.colorizer.gamma = 2
          sym.colorizer.minLabel = "Min: " + sym.colorizer.minLabel
          sym.colorizer.maxLabel = "Max: " + sym.colorizer.maxLabel

          l.symbology = sym