Next: Compass Gradient Operations Up: gradient Previous: The Gradient Operator
Digital Gradient
For discrete digital images, the derivative in gradient operation
becomes the difference
Two steps for finding discrete gradient of a digital image:
- Find the difference: in the two directions:
- Find the magnitude and direction of the gradient vector:
The differences in two directions and can be obtained by convolution with the following kernels:
- Roberts
or - Sobel (3x3)
- Prewitt (3x3)
- Prewitt (4x4)
Next: Compass Gradient Operations Up: gradient Previous: The Gradient OperatorRuye Wang 2013-11-08