BUILT-IN MATHEMATICA SYMBOL

# WatershedComponents

WatershedComponents[image]
computes the watershed transform of image, returning the result as a matrix in which positive integers label the catchment basins.

WatershedComponents[image, marker]
uses a binary image marker to indicate regions where basins may be created.

## Details and OptionsDetails and Options

• WatershedComponents[image] finds basins at each regional minimum in image.
• WatershedComponents[image, marker] finds basins only at the positions corresponding to foreground regions in a binary image marker.
• In WatershedComponents[image, marker], marker can be given either as an image, a graphics object, or a list of points in the standard image coordinate system, where x runs from 0 to width and y runs from 0 to height, and position corresponds to the bottom-left corner of the image.
• Typically, nonzero elements of marker are treated as seeds for the segmentation.
• In the label matrix returned by WatershedComponents, zeros represent positions that do not belong to any foreground component.
• WatershedComponents works with binary, grayscale, and other images.
• For multichannel images, WatershedComponents operates on the intensity averaged over all channels.
• WatershedComponents[image, Method->method] specifies the method to use to compute the watershed transform.
• The default setting is Method->"Watershed". Possible settings include:
•  "Watershed" morphological watershed method (Meyer) "Basins" modified watershed algorithm (Beucher, Meyer) "Rainfall" gradient descent or rainfall algorithm (Osma-Ruiz) "Immersion" watershed immersion algorithm (Vincent-Soille) {"MinimumSaliency",t} gradient descent algorithm that merges adjacent basins if their minimum boundary height is less than t
• The and methods return the watershed lines, represented as 0s in the label matrix.
• With the method, only four direct neighbors are considered adjacent. All other methods treat all eight pixels surrounding a given pixel as adjacent.
• With a setting , WatershedComponents finds a segmentation based only on directly connected pixels.

## ExamplesExamplesopen allclose all

### Basic Examples (3)Basic Examples (3)

Use watershed contours to illustrate the trabecular bone structure:

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Watershed segmentation of an image:

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Watershed segmentation of a gradient image:

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