Computing Watersheds

Lets you compute a Watershed segmentation, in which the labeled objects in the selected regions of interest or multi-ROI will be used as the seed points and the expanded components will then be overwritten into the initial ROIs or multi-ROI.

You should note that when you select Compute Watershed, you will be prompted to select a dataset as the landscape image, which will be used to compute a Sobel. You should also note that the selected ROIs need to provide enough information for the seed points to prevent bleeding from one region to another. In the example below, three regions of interest were created within ranges for the background (orange), media (yellow), and fibers (blue) and then the Watershed was computed.

You should note that when you select Compute Watershed, you will be prompted to select a dataset as the landscape image, which will be used to compute a Sobel. You should also note that the selected multi-ROI needs to provide enough information for the seed points to prevent bleeding from one region to another.

How to Compute a Watershed from Selected ROIs

1. Make sure that the ROIs you plan to use as the seed points can provide enough information to prevent bleeding from one region to another.
2. Select the regions of interest that will provide the seed points.
3. Right-click and then choose Compute Watershed in the pop-up menu.
4. Choose the dataset that will provide the local topography for the Watershed algorithm in the Choose the Dataset to Compute a Sobel dialog, as shown below.

   

5. Click OK.

   The Watershed is evaluated with the selected ROIs as the seeds and the computed Sobel image of the selected dataset as the landscape image.

   Wait for the expanded regions of interest to be computed and then overwritten into the initial ROIs.

How to Compute a Watershed from a Multi-ROI

1. Make sure that the multi-ROI you plan to use as the seed points can provide enough information to prevent bleeding from one labeled component to another.
2. Right-click the required multi-ROI and then choose Compute Watershed in the pop-up menu.
3. Choose the dataset that will provide the local topography for the Watershed algorithm in the Choose the Dataset to Compute a Sobel dialog, as shown below.

   

4. Click OK.

   The Watershed is evaluated with the labeled components in the multi-ROI as the seeds and the computed Sobel image of the selected dataset as the landscape image.

   Wait for the expansion of the labeled objects to be computed and then overwritten into the initial multi-ROI.