Documentation

imextendedmin

Extended-minima transform

Syntax

  • BW = imextendedmin(I,h) example
  • BW = imextendedmin(I,h,conn)

Description

example

BW = imextendedmin(I,h) computes the extended-minima transform, which is the regional minima of the H-minima transform. Regional minima are connected components of pixels with a constant intensity value, and whose external boundary pixels all have a higher value. h is a nonnegative scalar. By default, imextendedmin uses 8-connected neighborhoods for 2-D images and 26-connected neighborhoods for 3-D images. For higher dimensions, imextendedmin uses conndef(numel(size(I)),'maximal').

This function supports code generation (see Tips).

BW = imextendedmin(I,h,conn) computes the extended-minima transform, which is the regional minima of the H-minima transform. h is a nonnegative scalar.

Examples

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Perform Extended-Minima transform

Read image into the workspace.

I = imread('glass.png');

Calculate the extended-minima transform.

BW = imextendedmin(I,50);

Display the original image and the transformation side-by-side.

imshowpair(I,BW,'montage');

Input Arguments

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I — Input imagenonsparse numeric array of any dimension

Input array, specified as a nonsparse numeric array of any dimension.

Example: I = imread(‘glass.png'); BW = imextendedmax(I,80);

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical

h — h-maxima transform (default) | nonnegative scalar

h-maxima transform, specified as a nonnegative scalar.

Example: BW = imextendedmin(I,80);

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

conn — Connectivity8 (default) | 4 | 6 | 18 | 26 | 3-by-3-by- ...-by-3 matrix of zeroes and ones

Connectivity, specified as a one of the scalar values in the following table. By default, imextendedmin uses 8-connected neighborhoods for 2-D images and 26-connected neighborhoods for 3-D images. For higher dimensions, imextendedmin uses conndef(numel(size(I)),'maximal'). Connectivity can be defined in a more general way for any dimension by using for conn a 3-by-3-by- ...-by-3 matrix of 0s and 1s. The 1-valued elements define neighborhood locations relative to the center element of conn. Note that conn must be symmetric around its center element.

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

Example: BW = imextendedmin(I,80,4);

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Output Arguments

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BW — Transformed imagelogical array

Transformed image, returned as a logical array the same size as I.

More About

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Tips

  • This function supports the generation of C code using MATLAB® Coder™. Note that if you choose the generic MATLAB Host Computer target platform, the function generates code that uses a precompiled, platform-specific shared library. Use of a shared library preserves performance optimizations but limits the target platforms for which code can be generated. For more information, see Understanding Code Generation with Image Processing Toolbox.

    When generating code, the optional third input argument, conn, must be a compile-time constant.

References

[1] Soille, P., Morphological Image Analysis: Principles and Applications, Springer-Verlag, 1999, pp. 170-171.

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