How to Implement a PHP Image Edge Detection to Find Shapes using the Redstart Graphic BoxAction Classes - Redstart Graphic Library package blog

What is the Redstart Graphic Library Package
What is the Box Action

Example Code of Applying a Box Action Effect to Apply a Filter to Find Image Edges

How to Download the Redstart Graphic Library Package or Install it With PHP Composer

<?php

require '../autoload.php';

use Redstart\Graphic\Jpeg;
use Redstart\Graphic\Dimension;
use Redstart\Graphic\Action\BoxAction;
use Redstart\Graphic\Box;
use Redstart\Graphic\Action\Filter\ConvolutionFactor;

// load the resource (image) from file
$j = new Jpeg();
$j->loadFromFile('sample.jpg');

// create findeFilter from the ConvolutionFactor object
$findEdge = ConvolutionFactor::findEdge();

// create the box action and apply the findEdge filter to the second half of the 
// resource

$b = new BoxAction($findEdge, new Box(new Dimension(150, 400)));
$b->executeAction($j);

// save the created resource
try {
    header('Content-type:image/jpeg');
    $j->save(null);
} catch (Exception $e) {
    header('Content-type:text/html;charset=UTF-8');
    throw $e;
}