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## Lab: Dilation, Erosion, Opening, Closing

[Exercises] [Workspace]

Purpose: The purpose of this lab exercise is to demonstrate the basic principles in Mathematical Morphology of Dilation and Erosion, and the operations of Opening and Closing.

Activities:

1. Select the $DIP/data/angio.kdf image and display it.

   1. Glyphs:Input/Output:Data Files:User defined
   2. Glyphs:Visualization:Non-Interactive Display:Display Image

2. The input image is a grey-level image. Threshold the image at 128-level using the > (greater than) operator to produce a binary image. Display the thresholded image.

   1. Glyphs:Arithmetic:Comparison Operators:>
   2. Glyphs:Visualization:Non-Interactive Display:Display Image

3. Create a structuring element which is a 5x5 circle image using the Circle Image operator. Convert it to a structuring element using the Viff-> Str.El. operator.

   1. Glyphs:Khoros 1:Generate Data:Circle Image
   2. Glyphs:MMACH:Structural Element:Viff-> Str.El.

4. There are two basic tools in Mathematical Morphology: Dilation and Erosion. They can process both binary and grey-level images. These operators require the "structuring element" as second input.

   1. Use the circular structuring element created above to perform an Opening and a Closing operation on the binary image. Opening is an erosion followed by a dilation operation. Closing is a dilation followed by an erosion operation. Display the results.

      1. Glyphs:MMACH:Dilation and Erosion:Dilation
      2. Glyphs:MMACH:Dilation and Erosion:Erosion
      3. Glyphs:Visualization:Non-Interactive Display:Display Image

   2. Use the same circular structuring element to perform an Opening and a Closing operation on the grey-level image. Display the results.

      1. Glyphs:MMACH:Dilation and Erosion:Dilation
      2. Glyphs:MMACH:Dilation and Erosion:Erosion
      3. Glyphs:Visualization:Non-Interactive Display:Display Image

Exercises

1. Experiment with different sizes of structuring elements.

Khoros Workspace
Execute the visual program c9s4dil-ero-open-close.wk