Image Processing Toolbox    
imregionalmax

Find regional maxima

Syntax

Description

BW = imregionalmax(I) finds the regional maxima of I. imregionalmax returns a binary image, BW, the same size as I, that identifies the locations of the regional maxima in I. In BW, pixels that are set to 1 identify regional maxima; all other pixels are set to 0.

Regional maxima are connected components of pixels with the same intensity value, t, whose external boundary pixels all have a value less than t.

By default, imregionalmax uses 8-connected neighborhoods for 2-D images and 26-connected neighborhoods for 3-D images. For higher dimensions, imregionalmax uses conndef(ndims(I),'maximal').

BW = imregionalmax(I,CONN) computes the regional maxima of I using the specified connectivity. CONN may have any of the following scalar values.

Value
Meaning
Two-dimensional connectivities
4
4-connected neighborhood
8
8-connected neighborhood
Three-dimensional connectivities
6
6-connected neighborhood
18
18-connected neighborhood
26
26-connected neighborhood

Connectivity may be defined in a more general way for any dimension by using for CONN a 3-by-3-by- ...-by-3 matrix of 0's and 1's. The 1-valued elements define neighborhood locations relative to the center element of CONN. Note that CONN must be symmetric about its center element.

Class Support

I can be any nonsparse, numeric class and any dimension. BW is logical.

Example

See Also

conndef, imreconstruct, imregionalmin


  imreconstruct imregionalmin