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Editing thematic and classified pixels

Available with Image Analyst license.

Pixel Editor can be used to edit thematic and classified data. It contains tools to reclassify your data in the Edit group of the Pixel Editor tab, as well as Operations that can be applied to the data. Reclassification of thematic data is useful when you only need to correct the incorrectly classified pixels, instead of having to reclassify the entire dataset.

The Capture group has two tools: Copy Copy Region and Replace Replace Region. Copy allows you to specify an area in the region in which you want to copy the pixels, and then dynamically move and apply it to a different area. Replace allows you to specify a region that you want replaced, and lets you dynamically drag the working region to another area to be used to fill it. Both of these tools work on pixels from the current layer being edited, or you can choose another raster layer to work with in the map by specifying the Source Layer.

To interactively reclassify your data, first choose the field from the Current Class to reclassify. Next choose the New Class field to reclassify the original class data into the new class data. Then delineate a region to reclassify, use the Reclassify drop-down menu to choose which tool you want to use:

  • Reclassify Pixel Reclassify Pixel—Point to the pixel you want to reassign, and click the map display. You need to be zoomed into the pixel level to use this tool accurately.
  • Reclassify Object Reclassify Object—Use the circle tool to choose a group of contiguous pixels in which to reclassify. The center of the circle will determine the current class to reclassify, and the object will contain all contiguous pixels that are within the circle to be reclassified into the new class.
  • Reclassify Region Reclassify Region—Create a polygon to delineate the region in which to reclassify your pixels.

If you choose Any as your Current Class, all the pixels within your reclassify object or region will be updated to the New Class. If your class is not in the New Class drop-down list, you can click Add New Class. In the Add New Class window, fill in the information for your new class and click Ok to create your class. This will allow you to create a class, similar to the image classification workflow.

The operations that can be applied to editing classified pixels are described below.

IconOperationDescription
Expand

Expand

Expand specified zones of a region by a specified number of pixels, within the selected region.

The Number of Cells to expand the specified zones.

The Zone Values specify which zones you want to expand.

When the Exclude Region Intersections check box is checked, any regions that intersect the active region will be excluded from this operation.

Majority Filter

Majority Filter

Use the most common value within the filter window to set the value of each pixel within the selected region.

The Filter Size option allows you to choose the size of your filter window while performing the operation. A filter size of 8 means you are using an 8 by 8 filter window. Larger values result in more smoothing.

When the Exclude Region Intersections check box is checked, any regions that intersect the active region will be excluded from this operation.

Reclass Using Feature

Reclass Using Features

Integrates polygon information of a feature to reclassify your data within the selected region.

Input Features—Select the feature class to convert to raster format.

Field—Select the field to use to identify each feature.

Resolve overlap method—Determine how to manage features that overlap:

  • First—The overlapping areas will be assigned a value from the first dataset listed.
  • Last—The overlapping areas will be assigned a value from the last dataset listed.
  • Smallest—The overlapping areas will be assigned a value from the smallest feature.
  • Largest—The overlapping areas will be assigned a value from the largest feature.

When the Exclude Region Intersections check box is checked, any regions that intersect the active region will be excluded from this operation.

Set NoData

Set NoData

Set the pixels in the selected region as NoData pixels, for each band.

When the Exclude Region Intersections check box is checked, any regions that intersect the active region will be excluded from this operation.

Shrink

Shrink

Shrink the specified zones of a region by a specified number of pixels, within the selected region.

The Number of Cells to shrink the specified zones.

The Zone Values specify which zones you want to shrink.

When the Exclude Region Intersections check box is checked, any regions that intersect the active region will be excluded from this operation.

The Undo button Undo can be used to reverse the last action that was performed with the tools on the Pixel Editor tab. Undo can also be performed by pressing Ctrl+Z; this shortcut can also be used to undo actions that were performed within the Pixel Editor Operations pane. The Redo button Redo can be used to reverse the undo action that was performed with the tools on the Pixel Editor tab. Redo can also be performed by pressing Ctrl+Y; this shortcut can also be used to redo actions that were performed within the Pixel Editor Operations pane.

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