ImagickKernel::scale

Scales a kernel list by the given amount

Description

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

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; 
?>