Comparison tools
Use the comparison tools to conduct visual analysis and find differences in your imagery to complete your image-based task. The comparison tools contain features to highlight areas of interest through layer comparison and change detection.
Swipe tool
The Swipe tool allows you to interactively compare two layers vertically or horizontally in your Map Focus Panel. This makes it particularly easier to see what is underneath the layer you are focused on while analyzing your imagery.
The Primary and Comparison Layer drop-downs will always contain the Focused Imagery layers, but will also display images that you selected from the metadata table. Only two layers can be compared at a time. The web map is not available as a Comparison layer and is only available as an option for a Primary Layer.
To use the Swipe tool:
- Click the Tools menu in your imagery exploitation canvas.
- In the Display Tools list, click Swipe.
- Select a Primary Layer.
- Select a Comparison Layer.
Note:
The basemap is not available as a Comparison Layer. - Choose your preferred swipe bar direction.
Note:
The default swipe direction is vertical. - Click Apply.
- Click Reset from the Display Tools or from the main navigation menu to reset your layers and start again.
Note:
If the Map Focus Panel is not visible, the Swipe tool is disabled.
Flicker tool
The Flicker tool is used to visually compare images. The Flicker tool lets you display a layer underneath another layer by quickly turning it on and off in an automated way based on a defined rate. This can be useful for temporal change detection, data quality comparison, and other analysis you want to see between layers.
The Flicker tool is accessed from the Tools menu under Display Tools. The Map Focus Panel must be visible to use the Flicker tool. The Web Map and Focused Image Layer options are always available to you. The images you select from the metadata table are the images that will appear in your drop-down menu to apply the Flicker tool.
The default and minimum flicker interval rate is half of a second (500ms), while the maximum rate is five seconds (5000ms). To use the Flicker tool:
- Click the Tools menu in your imagery exploitation canvas.
- In the Display Tools list, click Flicker.
- Choose a Primary Layer.
- Choose a Secondary Layer.
- Choose your desired rate.
- Click Apply.
- Press Play.
The Pause and Stop buttons are enabled once Play is clicked, and the imagery layers are locked.
- You can press Pause or Stop to halt your Flicker tool.
- Click Reset to choose new images to compare and return to the default settings of the tool.
Detect Change tool
The Detect Change tool conducts automated pixel-based comparisons between two images selected in the image metadata table. This tool detects image change using multiple raster functions.
The tool must be run against two different rasterIds from a single image service that is query and catalog enabled. Once these images are selected, you can define the area of interest that the tool will run against. Results are returned as in-memory graphics that can be used for immediate visual comparison or can be used in imagery project reports.
To use the Detect Change tool, complete the following steps:
- Click the Tools menu in your imagery exploitation canvas
- In the Comparison Tools list, click Detect Change.
- Choose an Input Image 1.
If no images are selected in the image metadata table, a message will show in the view.
- Choose an Input Image 2. You cannot choose the same image as Input Image 1.
- Click Sketch Area of Interest.
- Draw and define an area of interest. Click Cancel Active Drawing to close the tool.
If the area of interest is drawn outside of the selected image extent, an error notification will display.
- Click Run.
Results are dynamically returned as graphics on your image.
- Click Reset to clear the results, selected images, and the drawn area of interest.
Note:
The tool is disabled if the active image service is non-query enabled or is a WMS or WMTS layer. If there is only one image in the image metadata table, the tool will also be disabled as a minimum of two selected images are required to run the tool.