RasterStretchColorizer

Synthèse

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.

Propriétés

Propriété	Explication	Type de données
band (Lecture et écriture)	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 (Lecture et écriture)	Provides access to the ColorRamp object.	ColorRamp
gamma (Lecture et écriture)	A double that represents the gamma value.	Double
invertColorRamp (Lecture et écriture)	A Boolean that reverses the color ramp's appearance.	Boolean
maxLabel (Lecture et écriture)	A string that represents the raster stretch maximum label that appears in the Contents pane or legend.	String
maxPercent (Lecture et écriture)	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 (Lecture et écriture)	A string that represents the raster stretch minimum label that appears in the Contents pane or legend.	String
minPercent (Lecture et écriture)	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 (Lecture et écriture)	A double that represents the standard deviation value. This parameter is only applied if the StretchType is set to StandardDeviation.	Double
stretchType (Lecture et écriture)	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 (Lecture seule)	Returns a string that represents the colorizer type.	String

Exemple de code

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