ImagickKernel::scale

(PECL imagick >= 3.3.0)

ImagickKernel::scale — Scales a kernel list by the given amount

Description

public ImagickKernel::scale(float $scale, int $normalizeFlag = ?): void

Scales the given kernel list by the given amount, with or without normalization of the sum of the kernel values (as per given flags). The exact behaviour of this function depends on the normalization type being used please see http://www.imagemagick.org/api/morphology.php#ScaleKernelInfo for details.

Parameters

scale

normalizeFlag

Imagick::NORMALIZE_KERNEL_NONE
Imagick::NORMALIZE_KERNEL_VALUE
Imagick::NORMALIZE_KERNEL_CORRELATE
Imagick::NORMALIZE_KERNEL_PERCENT

Return Values

Examples

Example #1 ImagickKernel::scale()

<?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;
    }


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

    $kernel = \ImagickKernel::fromMatrix($matrix);
    $kernelClone = clone $kernel;

    $output .= "Start kernel<br/>";
    $output .= renderKernelTable($kernel->getMatrix());
    
    
    $output .= "Scaling with NORMALIZE_KERNEL_VALUE. The  <br/>";
    $kernel->scale(2, \Imagick::NORMALIZE_KERNEL_VALUE);
    $output .= renderKernelTable($kernel->getMatrix());


    $kernel = clone $kernelClone;
    $output .= "Scaling by percent<br/>";
    $kernel->scale(2, \Imagick::NORMALIZE_KERNEL_PERCENT);
    $output .= renderKernelTable($kernel->getMatrix());
    
    $matrix2 = [
        [-1, -1, 1],
        [ -1, false,  1],
        [1, 1, 1],
    ];
    
    $kernel = \ImagickKernel::fromMatrix($matrix2);
    $output .= "Scaling by correlate<br/>";
    $kernel->scale(1, \Imagick::NORMALIZE_KERNEL_CORRELATE);
    $output .= renderKernelTable($kernel->getMatrix());

    return $output; 
?>