conndef

Create connectivity array

Syntax

conn = conndef(num_dims,type)

Description

conn = conndef(num_dims,type) returns the connectivity array defined by type for num_dims dimensions. type can have either of the values listed in this table.

Value

Description

'minimal'

Defines a neighborhood whose neighbors are touching the central element on an (N-1)-dimensional surface, for the N-dimensional case.

'maximal'

Defines a neighborhood including neighbors that touch the central element in any way; it is ones(repmat(3,1,NUM_DIMS)).

Several Image Processing Toolbox™ functions use conndef to create the default connectivity input argument.

Code Generation

conndef supports the generation of efficient, production-quality C/C++ code from MATLAB. All arguments must be compile-time constants. To see a complete list of toolbox functions that support code generation, see List of Supported Functions with Usage Notes.

Examples

The minimal connectivity array for two dimensions includes the neighbors touching the central element along a line.

conn1 = conndef(2,'minimal')

conn1 =
     0     1     0
     1     1     1
     0     1     0

The minimal connectivity array for three dimensions includes all the neighbors touching the central element along a face.

conndef(3,'minimal')

ans(:,:,1) =
     0     0     0
     0     1     0
     0     0     0

ans(:,:,2) =
     0     1     0
     1     1     1
     0     1     0

ans(:,:,3) =
     0     0     0
     0     1     0
     0     0     0

The maximal connectivity array for two dimensions includes all the neighbors touching the central element in any way.

conn2 = conndef(2,'maximal')

conn2 =
     1     1     1
     1     1     1
     1     1     1
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