This tool allows defining Regions of Interest (ROIs) over one raster layer. These regions or areas of interest can be used to derive statistics, classification processes, creation of masks or other applications.
To launch the ROIs edit tool for one layer you have to use the remote sensing toolbar by selecting “Raster layer” from the left button and “Area of interest” from the right button. You have to check that in the scrolling text window, the layer over which you want to draw the ROIs is selected.
The following window allows defining new ROIs linked to the selected layer.
ROI definition step by step
Click over New. A new entry line corresponding to the new ROI will appear in the table. By default, new ROI does not contain any geometry.
Select the geometry you want for the new ROI by activating the corresponding control.
1- The first control allows to add a point to the selected ROI.
2- The second one a linear geometry.
3- The last one a polygon geometry.
Once selected the tool, draw the selected geometry aver the layer.
Add geometries over an already existing ROI
To add a new geometry to a ROI, select the corresponding ROI in the table.
Activate the corresponding control according to the geometry to add
Once drawn the geometry on the view, the ROI will be updated.
Delete a ROI
To delete a ROI select the corresponding line in the table.
Once selected the ROI, click on Delete.
Save a ROI as a shapefile
This option allows to export defined ROIs into a shapefile. The fields of this shapefile will be: (ROI name), R (R value in RGB), G (G value in RGB), and B (B value in RGB).
For each type of geometry linked to the selected ROIs, a Polygon, Polyline or Point file will be created that will manage the corresponding geometries of all the ROIs defined in the table.
Load ROIs from a shapefile
This option allows loading in the ROI tool regions defined by a shapefile. It is compulsory that the shapefile has the fields name, R, G, B. Additional fields can be present as well. Once loaded the ROI, it can be edited in the same way of any other ROI created with the ROI edit tool.
