Edge detection is the most common approach in gray level discontinuity segmentation. An edge is a boundary between two regions having distinct intensity level. It is very useful in detecting of discontinuity in an image. When the image changes from dark to white or vice-versa
The changes of intensity, first-order derivative and second-order derivative
First-order derivatives
First-order derivatives responds whenever there is discontinuity in intensity level. It is positive at the leading edge and negative at the trailing edge.
Example an image f(x, y) and gradient operator f
Prewitt Edge operator
Prewitt Edge operator is used to detect edge in image processing through mask operator
Prewitt Edge operator mask
Prewitt Edge operator mask finds the horizontal edges is equivalent to gradient in the vertical direction and the mask compute the vertical edges is equivalent to gradient in the horizontal direction. Using these two masks passing to the intensity image, we can find out and component at different location in an image. So, we can find out the strength and direction of edge at that particular location (x, y)
Sobel Edge operator
Sobel Edge operator is used to detect edge in image processing through mask operator
