convol2d
discrete 2-D convolution, using fft.
Syntax
C = convol2d(A, B)
Parameters
- A
a real or complex 2-D array.
- B
a real or complex 2-D array.
- C
a real or complex 2-D array.
Description
convol2d uses fft to compute the full two-dimensional discrete
convolution. The dimensions of the result C are given by
size(A)+size(B)-1. The indices of the center element of
B are defined as floor((size(B)+1)/2).
Examples
s = [1 2 1; 0 0 0; -1 -2 -1] // Sobel horizontal edge kernel A = zeros(10,10); A(3:7,3:7) = 1 C = convol2d(s, A); clean(C)
--> s = [1 2 1; 0 0 0; -1 -2 -1] // Sobel horizontal edge kernel s = 1. 2. 1. 0. 0. 0. -1. -2. -1. --> A = zeros(10,10); A(3:7,3:7) = 1 A = 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. --> C = convol2d(s, A); --> clean(C) ans = 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 3. 4. 4. 4. 3. 1. 0. 0. 0. 0. 0. 1. 3. 4. 4. 4. 3. 1. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. -1. -3. -4. -4. -4. -3. -1. 0. 0. 0. 0. 0. -1. -3. -4. -4. -4. -3. -1. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
See also
History
| Version | Description |
| 5.4.0 | Function convol2d introduced. |
| Report an issue | ||
| << convol | Convolution - Correlation | corr >> |