ImagickKernel::addUnityKernel

(PECL imagick >= 3.3.0)

ImagickKernel::addUnityKernel — Adds a Unity Kernel to the kernel list

Description

public ImagickKernel::addUnityKernel(float $scale): void

Adds a given amount of the 'Unity' Convolution Kernel to the given pre-scaled and normalized Kernel. This in effect adds that amount of the original image into the resulting convolution kernel. The resulting effect is to convert the defined kernels into blended soft-blurs, unsharp kernels or into sharpening kernels.

Parameters

This function has no parameters.

Return Values

Examples

Example #1 ImagickKernel::addUnityKernel()


<?php



    function renderKernelTable($matrix) {
        $output = "<table class='infoTable'>";
    
        foreach ($matrix as $row) {
            $output .= "<tr>";
            foreach ($row as $cell) {
                $output .= "<td style='text-align:left'>";
                if ($cell === false) {
                    $output .= "false";
                }
                else {
                    $output .= round($cell, 3);
                }
                $output .= "</td>";
            }
            $output .= "</tr>";
        }
    
        $output .= "</table>";
    
        return $output;
    }

    $matrix = [
        [-1, 0, -1],
        [ 0, 4,  0],
        [-1, 0, -1],
    ];

    $kernel = \ImagickKernel::fromMatrix($matrix);
    $kernel->scale(1, \Imagick::NORMALIZE_KERNEL_VALUE);
    $output = "Before adding unity kernel: <br/>";
    $output .= renderKernelTable($kernel->getMatrix());
    $kernel->addUnityKernel(0.5);
    $output .= "After adding unity kernel: <br/>";
    $output .= renderKernelTable($kernel->getMatrix());
    
    
    $kernel->scale(1, \Imagick::NORMALIZE_KERNEL_VALUE);
    $output .= "After renormalizing kernel: <br/>";
    $output .= renderKernelTable($kernel->getMatrix());

    echo $output;

?>

Example #2 ImagickKernel::addUnityKernel()


<?php
function addUnityKernel($imagePath) {

    $matrix = [
        [-1, 0, -1],
        [ 0, 4,  0],
        [-1, 0, -1],
    ];

    $kernel = ImagickKernel::fromMatrix($matrix);

    $kernel->scale(4, \Imagick::NORMALIZE_KERNEL_VALUE);
    $kernel->addUnityKernel(0.5);


    $imagick = new \Imagick(realpath($imagePath));
    $imagick->filter($kernel);
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();

}

?>