Laplacian Filter

Requests for new features and wish-list items.
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Scottk
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Laplacian Filter

Post by Scottk »

In the layers module, how about adding a Laplacian filter? I knw the Sobel filter is there but adding a second order filter could provide more possibilities.
Scott K
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Re: Laplacian Filter

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Is this for edge detection/enhancement purposes? If so, would you find a Laplacian over Gaussian more useful?
Ivo Jager
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Scottk
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Re: Laplacian Filter

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Ivo,

Yes I am thinking about edge detection and enhancement. Please elaborate on how the Gaussian could be used. I would think that this would have the opposite effect.

Thanks.
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Re: Laplacian Filter

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Scottk wrote: Mon Nov 01, 2021 1:22 pm Ivo,

Yes I am thinking about edge detection and enhancement. Please elaborate on how the Gaussian could be used. I would think that this would have the opposite effect.

Thanks.
The problem with using a Laplacian filter alone is that the output is quite noisy and doesn't yield good/smooth edges. It is often combined with a Gaussian Filter.

I will implement this for the next beta.

In the meantime, also have a look at the Fractional Differentiation filter (paper here) in the Layer module, which is much more useful for astronomical purposes (e.g. it is very adept at visualising structures that are otherwise very difficult to see).
Ivo Jager
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Re: Laplacian Filter

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A Laplacian over Gaussian filter is now available in the Layer module in 1.8.519 beta. Any trouble, do let me know.
Ivo Jager
StarTools creator and astronomy enthusiast
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