3 - Image Processing: Filters

3 - Image Processing: Filters#

3.1 - Edge filters - vertical stripes#

  1. open the vertical_stripes.tif image (drag & drop, or File > Open)

  2. Image > Duplicate (IJ:28.9) (shift + d)

  3. apply horizontal Prewitt filter:

    • Process > Filters > Convolve

    • as kernel input (Prewitt):

    -1 -1 -1
 0  0  0
 1  1  1

    • click on OK.

    • do you understand the output of this process?

  4. select the original vertical_stripes.tif image and duplicate it again.

    • Image > Duplicate (IJ:28.9) (shift + d)

  5. apply vertical Prewitt filter:

    • Process > Filters > Convolve

    • as kernel input (Prewitt):

    -1  0  1
-1  0  1
-1  0  1

    • click on OK.

    • do you understand the output of this process?

3.2 - Edge filters - horizontal stripes#

The steps in this exercise are identical to 3.1, only the input image differs.

  1. open the horizontal_stripes.tif image (drag & drop, or File > Open)

  2. Image > Duplicate (IJ:28.9) (shift + d)

  3. apply horizontal Prewitt filter:

    • Process > Filters > Convolve

    • as kernel input (Prewitt):

        -1 -1 -1
    0 0 0
    1 1 1

    • click on OK.

    • do you understand the output of this process?

  4. select the original vertical_stripes.tif image and duplicate it again.

    • Image > Duplicate (IJ:28.9) (shift + d)

  5. apply vertical Prewitt filter:

    • Process > Filters > Convolve

    • as kernel input (Prewitt):

    -1  0  1
-1  0  1
-1  0  1

    • click on OK.

    • do you understand the output of this process?

3.3 - Edge filters - checkerboard#

The steps in this exercise are identical to 3.1 and 3.2 only the input image differs.

  1. open the checkerboard.tif image (drag & drop, or File > Open)

  2. Image > Duplicate (IJ:28.9) (shift + d)

  3. apply horizontal Prewitt filter:

    • Process > Filters > Convolve

    • as kernel input (Prewitt):

        -1 -1 -1
    0 0 0
    1 1 1

    • click on OK.

    • do you understand the output of this process?

  4. select the original checkerboard.tif image and duplicate it again.

    • Image > Duplicate (IJ:28.9) (shift + d)

  5. apply vertical Prewitt filter:

    • Process > Filters > Convolve

    • as kernel input (Prewitt):

    -1  0  1
-1  0  1
-1  0  1

    • click on OK.

    • do you understand the output of this process?

3.4 - Morphological filters - Binary#

  1. open the exercise_morphology.tif image (drag & drop, or File > Open)

  2. duplicate the image 4 times and name each copy as follow:

    • Eroded

    • Dilated

    • Closed

    • Opened

  3. apply binary morphological filters:

    • Process > Binary (Erode, Dilate, Close, Open)

    • Note: Make sure you apply the operation that corresponds to the name of each image.

  4. report findings

3.5 - Morphological filters - Gray#

  1. open the exercise_morphology.tif image (drag & drop, or File > Open)

  2. apply Gray Morphological filters:

    • Process > Morphology > Gray Morphology

  3. apply image opening with circular structuring element with radius 3 - removes noise

  4. Report: did it get rid of the noise?

  5. apply image opening with circular structuring element with radius 5

  6. report: did it get rid of the tentacles from the top-left object?

  7. with the line tool (IJ:19.2.1), measure the diameter of the holes in the bottom-right object.

  8. apply image closing with circular structuring element with radius slightly larger than the measured radius (diameter/2).

  9. report: did it get rid of the tentacles from the top-left circle?