edge detection: sobel horizontal

[t.mueller]

hi!
i want to detect edges with the sobel-operator.
labview-vision only has one sobel-vi, which is already detecting horizontal and vertical edges.
but i only want to see the horizontal edges.
using this matrix:
 1   2   1
 0   0   0
-1  -2  -1

has anybody already seen a vi that detects only the horizontal edges?
has anybody already written this vi / an idea to build this vi?

(information to sobel-operator: http://www.generation5.org/content/2002/im01.asp )

[GerdW]

Hi t.mueller,

this seems to be a perfect examples for learning LabView programming

I don't have vision installed so I cannot check the sobel operator. But from the description this is a simple matrix multiplication problem.
So convert your vision picture to an array, perform this matrix mult for each element of the picture and convert the array back to vision picture.
Maybe not the best solution, but will work too...

[GuenterMueller]

Hi t.mueller,
Gerd is right in what he said.
I expect that you don't want to work on arrays and want to operate on the image directly. You can use the VI "IMAQ Convolute" to apply a custom kernel on an image.
Regards, Guenter

[SHW]

I dont know much about labview vision software. I use robolab for labview. You can set a kernel vi. and define a matrix to display only veritcal or horizontal.