Is your raster so bright you have to wear shades?

Have you ever added a raster to an MXD and noticed that it looked different? Or created a mosaic dataset or raster catalog and suddenly, the rasters are so bright, you think, “What did ArcMap do to my raster?!”

Well, I’ll save you a Tech support call. There is a relatively simple reason why your raster is now so bright: there is a “stretch” being applied to the raster, making it brighter.  Applying a standard deviation to a raster with statistics is the default behavior in ArcMap because the stretch will improve the display of most rasters, but there are a few situations where the stretch is not appropriate.  

In order to turn off the stretch, open up the properties menu of the raster from the table of contents and click Symbology. The dialogue may differ depending on the type of data, but the components are the same. To see if your raster has a stretch, look below the “Display NoData as” button to the section indicated as – you guessed it – Stretch. Under that, you may notice the usual default setting as Standard Deviation. To turn off the stretch, simply switch that setting to “None” and click Apply or OK. Your raster should now look more like the original if you are using a mosaic dataset or raster catalog. 

So, why did this happen and where was the setting to control this effect?  Well, it depends on the version of ArcGIS Desktop you’re using. In ArcMap 9.3.1., the control will be under Tools > Option > Raster > General, titled “Display raster datasets with contrast stretching.” Uncheck the box.

In 9.3.1:

In ArcMap 10, the dialogue will be under Customize > Options > Raster > Raster Layer, titled “Stretch Type”. Select None. 

Both of the settings will prevent ArcMap from displaying the rasters with a stretch initially. By default, the stretch is automatically applied to all rasters with statistics added to ArcMap. Deleting the statistics will also prevent the display from being stretched. 

Related Articles

Jeff S. – Geodata Raster Support Analyst 


This entry was posted in Raster and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

11 Comments

  1. Pingback: Is your raster so bright you have to wear shades? | ArcGIS Resource Center

  2. damas74 says:

    Great job. Thank you.
    I want to tell you that with the ArcGIS Desktop 10 SP4, I can not save the “default stretch type” to “none”.
    Once I set, each time I restart ArcMap (or ArcCatalog), the configuration comes back to Standard Deviation.

    • Jeff S. says:

      Thanks for bringing this to our attention, you are not the only one. There is a bug report that has been created to capture this. As soon as it is published, I will add it here. I am sending more detailed instructions with the fix to your listed email address.

  3. danj says:

    Point of emphasis.

    Deleting the statistics is the only method that prevents this automatic stretching for an image service served through the Flex Viewer.

    -Dan

  4. Jeff S. says:

    NIM080358 has been published, which captures this behavior.
    http://support.esri.com/en/bugs/nimbus/TklNMDgwMzU4

    • jrskero1982 says:

      Jeff,

      In response to the Alternate solution, I cant seem to find the “StretchType” reg key.

      Alternate Solution
      Modifying the ‘StretchType’ registry key to 0 will set the default stretch option to ‘None.’ Although some systems need the ‘StretchType’ key to be removed to allow the default setting to be changed.

      • Jeff S. says:

        Depending on the version of ArcMap you are using, the keys may be slightly different. At 10.2.2 that I am currently using, there isn’t a key for this. You should be able to adjust the default raster settings without going to the registry key. If you are still using 10 SP 4 and having issues, then I recommend logging a Support case and have them take a look at your system with you.

  5. tift_tax says:

    Now if there was a way (in 9.3.1) to adjust images from ESRI’s WMS, such as Bing imagery ……

  6. amybrassieur says:

    This tip worked well for me – notice a comment that says deleting the statistics is the only way to prevent automatic stretching in an image service.

    What’s the downside of deleting the statistics? I don’t work much with rasters.

    I need to unstretch my image service for all my ArcGIS Explorer users.

  7. kavinda says:

    How to use “Alpha” channel option? I couldn’t find any hints in the help.
    Thanks
    -Kavinda