# Matrix5x5 node¶

This documentation is for version 1.0 of Matrix5x5 (eu.cimg.CImgMatrix5x5).

## Description¶

Compute the convolution of the input image with the specified matrix.

This works by multiplying each surrounding pixel of the input image with the corresponding matrix coefficient (the current pixel is at the center of the matrix), and summing up the results.

For example [-1 -1 -1] [-1 8 -1] [-1 -1 -1] produces an edge detection filter (which is an approximation of the Laplacian filter) by multiplying the center pixel by 8 and the surrounding pixels by -1, and then adding the nine values together to calculate the new value of the center pixel.

Uses 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

## Controls¶

Parameter / script name Type Default Function
/ matrix51 Double 0 Matrix coefficient.
/ matrix52 Double 0 Matrix coefficient.
/ matrix53 Double 0 Matrix coefficient.
/ matrix54 Double 0 Matrix coefficient.
/ matrix55 Double 0 Matrix coefficient.
/ matrix41 Double 0 Matrix coefficient.
/ matrix42 Double 0 Matrix coefficient.
/ matrix43 Double 0 Matrix coefficient.
/ matrix44 Double 0 Matrix coefficient.
/ matrix45 Double 0 Matrix coefficient.
/ matrix31 Double 0 Matrix coefficient.
/ matrix32 Double 0 Matrix coefficient.
/ matrix33 Double 0 Matrix coefficient.
/ matrix34 Double 0 Matrix coefficient.
/ matrix35 Double 0 Matrix coefficient.
/ matrix21 Double 0 Matrix coefficient.
/ matrix22 Double 0 Matrix coefficient.
/ matrix23 Double 0 Matrix coefficient.
/ matrix24 Double 0 Matrix coefficient.
/ matrix25 Double 0 Matrix coefficient.
/ matrix11 Double 0 Matrix coefficient.
/ matrix12 Double 0 Matrix coefficient.
/ matrix13 Double 0 Matrix coefficient.
/ matrix14 Double 0 Matrix coefficient.
/ matrix15 Double 0 Matrix coefficient.
Normalize / normalize Boolean Off Normalize the matrix coefficients so that their sum is 1.
(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.