Answers to questions are in answers.pdf

Hole Filling Algorithm

This library fills holes in images. Steps:

• Convert the source image to a grayscale format by taking the mean value of (r,g,b) values.
• Normalises color values from range [0-255] to [0.0-1.0]
• Assign -1 value to every pixel where defined as hole in the mask
• Find the the boundary of the hole (for either 8 or 4 connectivity)
• Applies the algorithm for every pixel in the hole
• Save the filled image in source image directory

NOTE: Mask image is the same height and width of the source image. A pixel is defined as 'hole pixel' iff its color value in the mask satisfies value > 0.5

Usage

./gradlew run --args='[image path] [mask path] [z] [epsilon] [pixel connectivity: 4/8]'

Recommend:

• Set z in range 2 <= z <= 25
• Set e < 1e-4

Example

./gradlew run --args='./images/tests/test1.jpg ./images/tests/test1_mask.jpg 2 0.00001 8'

source and mask

output

Unit tests

Finding the boundary of the hole was a quite a challenge for me compare to other actions. I tried to implement is as simple, efficient and readable as possible. I have built quite a few unit tests for this function using jUnit. To run all tests:

./gradlew test --tests holefill.ImageProcessTest

Overall tests

I have included some test images in /images/tests. To run:

./gradlew run --args='./images/tests/test1.jpg ./images/tests/test1_mask.jpg 2 0.00001 8'

 ./gradlew run --args='./images/tests/test2.jpg ./images/tests/test2_mask.jpg 2 0.00001 4'

./gradlew run --args='./images/tests/test3.jpg ./images/tests/test3_mask.jpg 27 0.00001 8'

./gradlew run --args='./images/tests/test4.jpg ./images/tests/test4_mask.jpg 2 0.00001 4'

./gradlew run --args='./images/tests/test5.jpg ./images/tests/test5_mask.jpg 24 0.00001 8'

./gradlew run --args='./images/tests/test6.jpg ./images/tests/test6_mask.jpg 3 0.00001 8'

Built With

• Gradle Wrapper - Dependency Management and Build Tool

Dependencies

• JUnit 4 - testing framework for the Java

Author

Ofir Abramovich