How do derivative masks work for finding edges in image?

1. How derivatives are used for edge detection?
2. What are various masks to detect edges in an image?
3. What is mask in edge detection?

How derivatives are used for edge detection?

In this method we take the 1st derivative of the intensity value across the image and find points where the derivative is maximum then the edge could be located. The gradient is a vector, whose components measure how rapid pixel value are changing with distance in the x and y direction.

What are various masks to detect edges in an image?

Here are some of the masks for edge detection. Prewitt Operator • Sobel Operator • Robinson Compass Masks • Kirsch Compass Masks • Laplacian Operator.

What is mask in edge detection?

Kirsch Compass Mask is also a derivative mask which is used for finding edges. Kirsch mask is also used for calculating edges in all the directions.