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I have a raster layer in arcgis which covers a large surface area. I would like to be able to zoom into specific areas of this raster and have it display only the range of values in the area I have zoomed to. Is this possible?

For example if the range of values for the entire raster is 0-255 but the range of values at the current extent is only 25-100 I would like the symbology to represent only those values between 25-100, until I zoom to a different scale.

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  • That would be a dynamic symbology and I'm not aware of any way to do it. As you mention, symbology and statistics are generated based on the entire raster extent. You can query specific areas, and with certain stretch renderers you can alter the appearance based on just the visible pixels, but you can't change the symbology.
    – Chris W
    Apr 16, 2015 at 19:44
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    Like when you use stretched symbology type: 'min/max' and set the statistics to 'From Current Display Extent'? (you need to scroll down to see that option) If the layer is expanded the min/max on screen is shown next to the colour ramp.
    – Michael Stimson
    Apr 16, 2015 at 23:20
  • @MichaelMiles-Stimson That is exactly what I was looking for! Thank you. Now I just wish there was a way to do this on a classified color ramp.
    – rgmrtn
    Apr 17, 2015 at 19:06
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    @MichaelMiles-Stimson yep, that's what I was referring to. Use that all the time when digitizing from b&w imagery.
    – Chris W
    Apr 18, 2015 at 0:33
  • @MichaelStimson This is reviving an old question, but I realized that you answered it for me. If you feel submitting your response as an answer. I will mark it as solved.
    – rgmrtn
    Nov 20, 2019 at 15:48

3 Answers 3

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You can ask ArcMap to stretch the raster based on the current view extent in the symbology dialog by changing the statistics part of the form (you will need to scroll down) to From Current Display Extent using any of the renderers (Min/Max, Standard deviation, Percent clip etc..): enter image description here enter image description here

Using this option is usually good for being able to visualize an elevation model extent with maximum contrast, like panning along a watercourse from headwater to sea, but in the instance where your image is noisy or doesn't have much variation in height you may need to change the renderer to better display or exclude values on the screen.

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You can accomplish this with multiple layers pointing to the same raster source. Give each layer its own separate scale range and symbology.

If you wanted to have a particular symbology between 1:25 and 1:100, you'd set those values on the General tab as shown below. Then choose the appropriate symbology on the Symbology tab.

Then you might have, say, two additional layers: one covering 1:1 - 1:24, and one covering 1:101 - 1:255.

enter image description here

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    This doesn't really work for what the asker is trying to do. If you're looking for different symbology at different scales, this is the way to go. But what they want is a symbology that's based on a classification of values visible in the window at any given scale (so the symbology is actually dependent on visible data values/range, not the scale).
    – Chris W
    Apr 18, 2015 at 0:35
  • Ah yes. That was not clear to me. I will suggest an edit to the question.
    – Andy
    Apr 21, 2015 at 11:50
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Try this out:

import arcpy, os, traceback, sys
from arcpy import env
env.workspace="in_memory"
env.overwriteOutput = True

try:
    def showPyMessage():
        arcpy.AddMessage(str(time.ctime()) + " - " + message)
    mxd = arcpy.mapping.MapDocument("CURRENT")
    color_layer=arcpy.mapping.ListLayers(mxd,"silver.tif")[0]
    wholeRaster=arcpy.Raster(color_layer.dataSource)
    df = arcpy.mapping.ListDataFrames(mxd)[0]
    ext=df.extent
    ext='%s %s %s %s' %(ext.XMin, ext.YMin,ext.XMax,ext.YMax)
    arcpy.Clip_management (wholeRaster, ext, "victim")
    desc = arcpy.GetRasterProperties_management("victim", "MINIMUM")
    minV = int(desc.getOutput(0))
    desc = arcpy.GetRasterProperties_management("victim", "MAXIMUM")
    maxV = int(desc.getOutput(0))
    arcpy.AddMessage('%s %s' %(minV,maxV))
    intervals=5; valueList=[]
    dV=(maxV-minV)/intervals
    for i in range(intervals+1):
        valueList.append(minV+int(dV*i))
    color_layer.symbology.valueField="Value"
    color_layer.symbology.classBreakValues =valueList
    arcpy.RefreshActiveView()
    arcpy.RefreshTOC()
except:
    message = "\n*** PYTHON ERRORS *** "; showPyMessage()
    message = "Python Traceback Info: " + traceback.format_tb(sys.exc_info()[2])[0]; showPyMessage()
    message = "Python Error Info: " +  str(sys.exc_type)+ ": " + str(sys.exc_value) + "\n"; showPyMessage()
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  • Could you edit your question to include what the code does? It will help folks who aren't as code-savvy decide whether to try to decipher it. Thanks :)
    – Nova
    Jan 12, 2018 at 14:47

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