XueyanLi-FinalProject

7/27/2019 XueyanLi-FinalProject

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CIS581 Presentation

Morphological Operations

Presented by: Xueyan LiSupervised by: Longin Jan Lateckie


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Presentation Outline

Terminology and properties of Morphology Operations

Structure element

Four morphological Principles

Iterative Morphological Operations

Matlab Programs and results images for each operation


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Introduction---Morphology Operations

Terminology

Morphology:a broad set of image processing operations that

process images based on shapes.

Morphological operations apply a structuring elements to an

input image, creating an output image of the same size.

Properties

Morphological operations simplify images, and quantify and

preserve the main shape characteristics of objects.


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Four morphological principles

Dilation

Erosion

Opening

Closing


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Relationship of four operations

Dilation and Erosion are the basic operations, can be

combined into more complex sequences.

Erosion and dilation are not invertible operations ---if an

image is eroded and dilated, the original image is not re-

obtained.

The combination of Erosion and dilation constitutes new

operations ----opening and closing. They are the most

useful morphological filtering.


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Structuring element

Morphological operations can be customized for anapplication by the proper selection of the structuring element,which determines exactly how the object will be dilated oreroded.

matlab function strel() can create many kinds of structuringelement:

dish-shaped,

diamond-shaped,

ball-shaped,

square

flat linear with length LEN

arbitrary flat or a nonflat with the specified neighborhood


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Dilation

Dilation allows objects to expand, then potentially filling in small

holes and connecting disjoint object.

Performance: laying the structuring element on the image and

sliding it across the image.

1) If the origin of the structuring element coincides with a 0 in

the image, there is no change; move to the next pixel.

2) If the origin of the structuring element coincides with a 1 inthe images, perform the OR logic operation on all pixels within

the structuring element.


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My input images


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Matlab programming ---dilation

%Read image

I = imread(ford.tiff');

figure('Name', 'original');

imshow(I);

%create structuring elements

% 11-by-11 square

se1 = strel('square',11);

%Apply dilation operationfigure('Name', 'Dilate');

Idilate1 = imdilate(I,se1);

%Show the result image

subplot(1,1,1), imshow(Idilate1),

title('11x11 square');

original image (above)

Image after dilation (below)


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Erosion

Erosion shrinks objects by etching away (eroding) their

boundaries.

Performance:


the image, there is no change; move to the next pixel.


the image, and any of the 1 pixels in the structuring element

extend beyond the object (1 pixels) in the image, then

change the 1 pixel in the image to a 0;


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Matlab programming ---erosion

%Read image



imshow(I);


% 11-by-11 square


%Apply erosion operationfigure('Name', 'Erode');

Ierode1 = imerode(I,se1);


subplot(1,1,1), imshow(Ierode1),



Image after erosion (below)


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Opening

Opening consists of an erosion followed by a dilation and can

be used to eliminate all pixels in regions that are to small to

contain the structuring element.

In this case the structuring element is often called a probe,

because it is probing the image looking for small objects to

filter out of the image.


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Matlab programming--- opening

%Read image



imshow(I);


% 11-by-11 square


%Apply the open opration

figure('Name', 'Open');

Iopen1 = imopen(I,se1);


subplot(1,1,1), imshow(Iopen1), title('11x11

square');


Image after opening (below)


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Closing

Closing consists of a dilation followed by an erosion and

connects objects that are close to each other. It can be used

to fill in holes and small gaps.


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Matlab programming ---closing

%Read image



imshow(I);


% 11-by-11 square


%Apply close operationfigure('Name', Close');

Iclose1 = imclose(I,se1);


subplot(1,1,1), imshow(Iclose1),



Image after closing (below)


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Iterative Morphological Operations

We can apply one or several operations to an image

iteratively.

InputImage ---(apply an operation) outputImage1---(apply the operation again) outputImage2and so on..until get your desired image


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Matlab program

iterative operation of dilation (1)

Original image after 1 dilation

after 5th dilations after inf dilations


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Matlab program

iterative operation of dilation (2)

Original image after 1 dilation

after 5th dilations after inf dilations


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Matlab program

iterative operation of erosion (1)

Original image after 1 erosion

after 5th erosions after inf erosions


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Matlab program

iterative operation of erosion (2)

Original image after 1 erosion

after 5th erosions after inf erosions


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Matlab program

iterative operation of opening (1)

Original image after 1 opening

after 5th openings after inf openings


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Matlab program

iterative operation of opening (2)

Original image after 1 opening

after 5th openings after inf openings

l b


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Matlab program

iterative operation of closing (1)

Original image after 1 closing

after 5th closings after inf closnings

l b


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Matlab program

iterative operation of closing (2)

Original image after 1 closing

after 5th closings after inf closings


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Morphological operations

on gray-level image

Original image Image after dilation Image after erosion


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My programming files

1. morphor.m

2. bwmorhpr.m

If you are more interested in this topic, you can try to play

the source code with a updated Matlab. Im sure a lot of fun

there!


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Thank you !

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