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MorphologicalComponents[image]

gives an array in which each pixel of image is replaced by an integer index representing the connected foreground image component in which the pixel lies.

MorphologicalComponents[image,t]

treats values above t as foreground.

MorphologicalComponents[video,…]

computes connected components in frames of video.

Details and Options
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Options  
CornerNeighbors  
Method  
Padding  
Applications  
Neat Examples  
See Also
Tech Notes
Related Guides
History
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MorphologicalComponents

MorphologicalComponents[image]

gives an array in which each pixel of image is replaced by an integer index representing the connected foreground image component in which the pixel lies.

MorphologicalComponents[image,t]

treats values above t as foreground.

MorphologicalComponents[video,…]

computes connected components in frames of video.

Details and Options

  • MorphologicalComponents, also known as image connected components, is a binary image segmentation technique that segments image foreground based on pixel connectivity.
  • MorphologicalComponents assigns sequential integers to different connected components and 0 to pixels that correspond to the background in the image.
  • MorphologicalComponents[image] is equivalent to MorphologicalComponents[image,0].
  • MorphologicalComponents works with binary, grayscale, and other images.
  • The following options can be specified:
  • CornerNeighbors Truewhether to include corner neighbors
    Method "Connected"connectivity method
    Padding 0padding method to use
  • The following Method settings can be specified:
  • "Connected"labels connected components
    "Nested"labels nested connected components
    "Convex"labels objects within non-overlapping convex regions
    "ConvexHull"finds non-overlapping convex hulls
    "BoundingBox"finds non-overlapping bounding boxes
    "BoundingDisk"finds non-overlapping bounding disks
  • MorphologicalComponents[image,Method->"Connected"] also works with Image3D objects.

Examples

open all close all

Basic Examples  (1)

Find the connected components in a binary image:

Wolfram Language code: MorphologicalComponents[[image]]// Colorize

Scope  (4)

Segment a binary image:

Wolfram Language code: MorphologicalComponents[[image]]//Colorize

Segment a grayscale image, using all nonzero pixels as foreground:

Wolfram Language code: MorphologicalComponents[[image]]//Colorize

Specify a background threshold:

Wolfram Language code: MorphologicalComponents[[image], .2]//Colorize

Connected component labels:

Wolfram Language code: MorphologicalComponents[(⁠| | | | | | - | - | - | - | | 0 | 0 | 1 | 2 | | 0 | 0 | 3 | 4 | | 5 | 0 | 0 | 0 | | 6 | 7 | 0 | 0 |⁠)] // MatrixForm

Connected components of a 3D image:

Wolfram Language code: MorphologicalComponents[[image]]//Colorize

Options  (10)

CornerNeighbors  (3)

8-connected objects:

Wolfram Language code: MorphologicalComponents[[image]]//MatrixForm

4-connected objects:

Wolfram Language code: MorphologicalComponents[[image], CornerNeighbors -> False] // MatrixForm

Connectedness in 3D:

Wolfram Language code: i = [image];
Wolfram Language code: Colorize@MorphologicalComponents[i, CornerNeighbors -> #]& /@ {True, False}

Method  (6)

By default the "Connected" method is used:

Wolfram Language code: MorphologicalComponents[[image]]// Colorize

Find the bounding boxes of connected components:

Wolfram Language code: MorphologicalComponents[[image], Method -> "BoundingBox"]// Colorize

Find the non-overlapping bounding disks:

Wolfram Language code: MorphologicalComponents[[image], Method -> "BoundingDisk"]// Colorize

Find components whose convex hulls do not overlap:

Wolfram Language code: MorphologicalComponents[[image], Method -> "Convex"]// Colorize

Non-overlapping convex components:

Wolfram Language code: MorphologicalComponents[[image], Method -> "ConvexHull"]// Colorize

Label each component the same as its embedding component:

Wolfram Language code: MorphologicalComponents[[image], Method -> "Nested"]//Colorize

Padding  (1)

By default, zero padding is used:

Wolfram Language code: i = [image];
Wolfram Language code: MorphologicalComponents[i]//Colorize

Using Padding->1, all components connected to the border are assumed to be connected:

Wolfram Language code: MorphologicalComponents[i, Padding -> 1]//Colorize

Applications  (2)

Count the number of bright spots, specifying an explicit thresholding value:

Wolfram Language code: MorphologicalComponents[[image], 0.8]//Max

Count the number of pixels in each connected component of an image:

Wolfram Language code: Tally[Flatten[MorphologicalComponents[[image]]]]

Neat Examples  (1)

Find connected regions in a map:

Wolfram Language code: MorphologicalComponents[[image]] //Colorize
Wolfram Research (2008), MorphologicalComponents, Wolfram Language function, https://reference.wolfram.com/language/ref/MorphologicalComponents.html (updated 2025).

Text

Wolfram Research (2008), MorphologicalComponents, Wolfram Language function, https://reference.wolfram.com/language/ref/MorphologicalComponents.html (updated 2025).

CMS

Wolfram Language. 2008. "MorphologicalComponents." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2025. https://reference.wolfram.com/language/ref/MorphologicalComponents.html.

APA

Wolfram Language. (2008). MorphologicalComponents. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/MorphologicalComponents.html

BibTeX

@misc{reference.wolfram_2026_morphologicalcomponents, author="Wolfram Research", title="{MorphologicalComponents}", year="2025", howpublished="\url{https://reference.wolfram.com/language/ref/MorphologicalComponents.html}", note=[Accessed: 13-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_morphologicalcomponents, organization={Wolfram Research}, title={MorphologicalComponents}, year={2025}, url={https://reference.wolfram.com/language/ref/MorphologicalComponents.html}, note=[Accessed: 13-June-2026]}