imageOptimise.class.php

<?php

ini_set('max_execution_time', 600); // 10 minutes

class OptimiseImage
{
    private $baseDir   = '/';
    private $inputDir  = 'input';
    private $outputDir = 'output/large';
    private $tmpDir    = 'tmp';
    private $files     = [];

    private $fullDir = '';
    private $currentFileNameName = '';

    public function __construct()
    {
        $baseDir = realpath(dirname(__FILE__) . '/..');
        $fullDir = $baseDir . '/' . $this->inputDir . '/';

        $this->baseDir = $baseDir;
        $this->fullDir = $fullDir;
    }

    private function getFiles()
    {
        $dir = $this->fullDir;
        $files = [];

        if (!is_dir($dir)) {
            throw new Exception("Dir '$dir' not found", 1);
        }

        $files = scandir($dir);

        // Remove the periods from the start of the array
        $files = array_filter($files, function($item) {
            return !is_dir('../' . $item);
        });

        $this->files = $files;

        return $files;
    }

    private function save($img, $quality = 80, $tmp = false)
    {
        $tmpDir = $this->baseDir . '/' . $this->tmpDir;
        $outputDir = $this->baseDir . '/' . $this->outputDir;
        $output = '';
        $fileExists = false;

        if ($tmp) {
            if (!is_dir($tmpDir)) {
                mkdir($tmpDir, true);
            }

            $output = $tmpDir . '/' . $this->currentFileName;
        } else {
            $output = $outputDir . '/' . $this->currentFileName;
        }

        $fileExists = file_exists($output);

        if (!$fileExists) {
            imagejpeg($img, $output, $quality);
        }
    }

    private function cleanup()
    {
        $this->currentFileName = '';

    }

    private function compress($quality)
    {
        $file = $this->currentFileName;
        $img  = imagecreatefromjpeg($this->inputDir . '/' . $file);

        $this->save($img, $quality);

        return $this;
    }

    public function optimise($quality = 80)
    {
        $files = $this->getFiles();

        if (empty($files)) {
            throw new Exception("Cannot process 0 files", 1);
        }

        foreach ($files as $file) {
            if ($this->isValidImage($file)) {
                $this->currentFileName = $file;

                $this->compress($quality);
            }
        }
    }

    /**
     * Crude check to see if a given filename extension matches a known
     * image extension
     * @param  string  $file
     * @return boolean
     */
    public function isValidImage($file)
    {
        $extension = strtolower(substr($file, strrpos($file, '.') + 1));
        $fileUrl = $this->inputDir . '/' . $file;

        switch ($extension) {
        case 'jpeg':
        case 'jpg':
            $validImage = @imagecreatefromjpeg($fileUrl);
            break;

        case 'png':
            $validImage = @imagecreatefrompng($fileUrl);
            break;

        case 'gif':
            $validImage = @imagecreatefromgif($fileUrl);
            break;

        default:
            $validImage = false;
        }

        if (!$validImage) {
            return false;
        }

        return true;
    }

}