qiqi473 / sobel

Implementation of Sobel Filter in Verilog

Implementation of Sobel Filter on Verilog

The code currently computes convolution of an image with a fixed kernel to find a gradient. By extending the logic to two gradients along x and y axes, and computing the square root of the squared sums, Sobel filter can be implemented.

The convolution approach has been adopted from this paper.

Example

Assume we have a 5*5 image.

1	2	3	4	5
0	1	0	1	0
1	2	3	4	5
0	1	0	1	0
1	2	3	4	5

and a 3*3 kernel

1	2	1
0	0	0
1	2	1

The output result would be

7	12	16
4	4	4
7	12	16

Simulation

The result can be verified from the screenshot here. Note that the pxl_out bits are considered only when the valid bit is 1.