Remove anomalies from elevation data

Disponible avec une licence Image Analyst.

If your elevation raster has spikes, holes, outlier values, or noise, you can edit these pixels using Pixel Editor.

This workflow will follow these four steps:

1. Start a Pixel Editor session.
2. Select the region to clean up.
3. Remove noise from your elevation.
4. Save your edits.

Start a Pixel Editor session

Pixel Editor can only edit one layer at a time per map view. The contextual layer used to start the Pixel Editor session is the only layer that can be edited in that map view. To edit another layer in the map, you must first close Pixel Editor, select the other layer in the Contents pane, and reopen Pixel Editor to operate on that layer.

1. In the Contents pane, highlight the elevation raster dataset layer that you want to edit.

   Pixel Editor can only edit raster dataset sources.

2. Click the Imagery tab.
3. Click the Pixel Editor button .

You are now able to edit your elevation raster dataset using Pixel Editor.

Select the region

Edits using Pixel Editor are performed on the region you specify. The Region drop-down menu allows you to choose which tool you want to use to specify your region. The Region Mode allows you to create a new region, or modify an existing region. In this workflow, we will specify an area to edit, and then perform an operation to clean up the data.

1. Zoom in to the area where you want to remove pixel anomalies from your data.
2. In the Pixel Editor tab, click the drop-down arrow below Region Mode, and choose New .
3. Click the drop-down arrow below Region, and choose Polygon . Notice that there are some pixels in the data that look significantly different than most of the surrounding pixels.
4. Draw a polygon around the area of interest; double-click to end the polygon.

   

Edit the elevation data

There are several ways we can correct or edit elevation data. In this workflow, we will remove the anomalies or noise from the data. An outlier is defined as pixels that are different than surrounding pixels by a statistical threshold.

1. Click the Operations drop-down menu, and choose Outlier Filter from the gallery.

   The Pixel Editor Operations pane will appear.

2. Make sure that the region you created is selected. If not, click the Select tool from the Region group, and select the region.
3. In the Pixel Editor Operations pane, change the Threshold to 3 standard deviations. A higher value will choose pixels to filter that are further from the average pixel value within the filter window. The Filter Size specifies the size of the window for filtering the outlier pixels.
4. Click Apply.

   The outliers are assigned a new value determined by the pixel values contained in the specified filter window.

   

Save your edits

To commit your edits back to the data source, you must save them.

1. In the Save group, click the Save button .

   To save your edits without affecting the source data, save to a new file. In the Save group, click the Save As button , and specify a location and file name for the new file.

2. Click Close Pixel Editor in the Close group when you finish editing the raster dataset.