Laplacian node

This documentation is for version 4.0 of Laplacian (net.sf.cimg.CImgLaplacian).

Description

Blur input stream, and subtract the result from the input image. This is not a mathematically correct Laplacian (which would be the sum of second derivatives over X and Y).

Uses the ‘vanvliet’ and ‘deriche’ functions from the CImg library.

CImg is a free, open-source library distributed under the CeCILL-C (close to the GNU LGPL) or CeCILL (compatible with the GNU GPL) licenses. It can be used in commercial applications (see http://cimg.eu).

Inputs

Input	Description	Optional
Source		No
Mask		Yes

Controls

Parameter / script name	Type	Default	Function
Size / `size`	Double	x: 3 y: 3	Size (diameter) of the filter kernel, in pixel units (>=0). The standard deviation of the corresponding Gaussian is size/2.4. No blur is applied if size < 0.24 (Gaussian and quasi-Gaussian) or <= 1 (box, triangle and quadratic).
Uniform / `uniform`	Boolean	Off	Apply the same amount of blur on X and Y.
Filter / `filter`	Choice	Gaussian	Bluring filter. The quasi-Gaussian filter should be appropriate in most cases. The Gaussian filter is more isotropic (its impulse response has rotational symmetry), but slower. Quasi-Gaussian (quasigaussian): Quasi-Gaussian filter (0-order recursive Deriche filter, faster) - IIR (infinite support / impulsional response). Gaussian (gaussian): Gaussian filter (Van Vliet recursive Gaussian filter, more isotropic, slower) - IIR (infinite support / impulsional response). Box (box): Box filter - FIR (finite support / impulsional response). Triangle (triangle): Triangle/tent filter - FIR (finite support / impulsional response). Quadratic (quadratic): Quadratic filter - FIR (finite support / impulsional response).
(Un)premult / `premult`	Boolean	Off	Divide the image by the alpha channel before processing, and re-multiply it afterwards. Use if the input images are premultiplied.
Invert Mask / `maskInvert`	Boolean	Off	When checked, the effect is fully applied where the mask is 0.
Mix / `mix`	Double	1	Mix factor between the original and the transformed image.