PHP | ImagickKernel addUnityKernel() Function

The ImagickKernel::addUnityKernel() function is an inbuilt function in PHP which is used to add a given amount of the ‘Unity’ Convolution Kernel to the given kernel. This function is used to convert the defined kernels into blended soft-blurs, unsharp kernels or into sharpening kernels.

Syntax:

bool ImagickKernel::addUnityKernel( float $scale )

Parameters: This function accepts a single parameter $scale which holds the scale of unity kernel.

Return Value: This function returns TRUE on success.

Below programs illustrate the ImagickKernel::addUnityKernel() function in PHP:

Program 1:

<?php

// Create a new imagick object
$imagick = new Imagick(
'https://media.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-13.png');

// Create a kernel from matrix
$kernel = ImagickKernel::fromMatrix(
        [[-1, 0, -1], [0, 4, 0], [-1, 0, 0]]);

// Add the Unity Kernel
$kernel->addUnityKernel(0.7);

// Add the filter
$imagick->filter($kernel);

// Show the output
$imagick->setImageFormat('png');
header("Content-Type: image/png");
echo $imagick->getImageBlob();
?>

Output:

Program 2:

<?php

// Create a kernel from matrix
$kernel = ImagickKernel::fromMatrix(
        [[-3, 0, -2], [ 3, 4,  2], [-1, 0, -1]]);

echo "Before adding unity kernel: <br/>";
print("<pre>".print_r($kernel->getMatrix(), true)."</pre>");

// Add the Unity Kernel
$kernel->addUnityKernel(12);

echo "After adding unity kernel: <br/>";
print("<pre>".print_r($kernel->getMatrix(), true)."</pre>");
?>

Output:

Before adding unity kernel:
Array
(
    [0] => Array
        (
            [0] => -3
            [1] => 0
            [2] => -2
        )

    [1] => Array
        (
            [0] => 3
            [1] => 4
            [2] => 2
        )

    [2] => Array
        (
            [0] => -1
            [1] => 0
            [2] => -1
        )

)
After adding unity kernel:
Array
(
    [0] => Array
        (
            [0] => -3
            [1] => 0
            [2] => -2
        )

    [1] => Array
        (
            [0] => 3
            [1] => 16
            [2] => 2
        )

    [2] => Array
        (
            [0] => -1
            [1] => 0
            [2] => -1
        )

)

Reference: https://www.php.net/manual/en/imagickkernel.addunitykernel.php