Delete no more used Product Images on Magento

shell_delete_unused_images.php

<?php
require_once 'abstract.php';

class Mage_Shell_CheckImages extends Mage_Shell_Abstract
{
    const CATALOG_PRODUCT = '/catalog/product';

    const CACHE = '/cache/';

    public function run()
    {
        if ($this->getArg('help')) {
            echo $this->usageHelp();
            return;
        }

        $media = Mage::getBaseDir('media');
        $debug = $this->getArg('debug');
        $dryrun = $this->getArg('dry') ? true : false ;
        $includeCache = $this->getArg('cache');

        $imagesOnDb = array();
        $imagesOnDisk = array();
        $setup = new Mage_Core_Model_Resource_Setup('core_setup');
        /** @var Varien_Db_Adapter_Pdo_Mysql $connection */
        $connection = $setup->getConnection();

        $sql = "SELECT DISTINCT value
FROM (
	SELECT value
	FROM  `{$setup->getTable('catalog_product_entity_media_gallery')}`
	WHERE attribute_id
	IN (SELECT attribute_id FROM `{$setup->getTable('eav_attribute')}` WHERE `attribute_code` in ('media_gallery') AND entity_type_id = 4)
	UNION
	SELECT value
	FROM  `{$setup->getTable('catalog_product_entity_varchar')}`
	WHERE attribute_id
	IN (SELECT attribute_id FROM `{$setup->getTable('eav_attribute')}` WHERE `attribute_code` in ('image','small_image','thumbnail') AND entity_type_id = 4)
) AS T";
        $result = $connection->query($sql);
        foreach ($result->fetchAll() as $rec) {
            $imagesOnDb[$rec['value']] = 1;
        }
        $imagesOnDb = array_keys($imagesOnDb);
        if ($debug) print_r(array_slice($imagesOnDb, 0, 100));

        if ($debug) echo $media . "/*\n";
        $skip = strlen($media . self::CATALOG_PRODUCT);
        foreach (glob($media . self::CATALOG_PRODUCT . '/?/?/*.*', GLOB_MARK) as $img) {
            $imagesOnDisk[] = substr($img, $skip);
        }
        if ($debug) print_r(array_slice($imagesOnDisk, 0, 100));

        $imagesToDelete = array_diff($imagesOnDisk, $imagesOnDb);
        if ($debug) {
            print_r($imagesToDelete);
        } else {
            foreach ($imagesToDelete as $x) {
                if ($dryrun) {
                    echo 'rm '.$media . self::CATALOG_PRODUCT . $x.PHP_EOL;
                } else {
                    @unlink($media . self::CATALOG_PRODUCT . $x);
                }
            }
        }

        if ($debug) {
            echo "\r\n";
        }

    }

    public function usageHelp()
    {
        return <<<USAGE
Usage: php -f check_images.php
    debug       debug mode
    cache       remove cache images too
    dry         dryrun


USAGE;
    }
}

$shell = new Mage_Shell_CheckImages();
$shell->run();