Howtosignalprocessing
- What is Sobel operator used for?
- What is Sobel derivative?
- What are the derivative operators useful in image segmentation?
- Why second derivative operation is not normally used for edge detection?
What is Sobel operator used for?
The Sobel operator performs a 2-D spatial gradient measurement on an image and so emphasizes regions of high spatial frequency that correspond to edges. Typically it is used to find the approximate absolute gradient magnitude at each point in an input grayscale image.
What is Sobel derivative?
The Sobel Operator is a discrete differentiation operator. It computes an approximation of the gradient of an image intensity function. The Sobel Operator combines Gaussian smoothing and differentiation.
What are the derivative operators useful in image segmentation?
The Prewitt and Sobel operators are among the most used in practice for computing digital gradients. The Prewitt masks are simpler to implement than the Sobel masks, but the latter have slightly superior noise-suppression characteristics, an important issue when dealing with derivatives.
Why second derivative operation is not normally used for edge detection?
If there is a significant spatial change in the second derivative, an edge is detected. 2nd Order Derivative operators are more sophisticated methods towards automatized edge detection, however, still very noise-sensitive. As differentiation amplifies noise, smoothing is suggested prior to applying the Laplacians.
