*******CODIGO LINK.PHP DE CARPETA CLASSES***********

public function getImageLink2($name, $ids, $type = null)
    {
   if(isset($ids))
   {
    $over_image = Db::getInstance()->getRow('SELECT id_image FROM '._DB_PREFIX_.'image WHERE id_product = '.(int)($ids).' AND position = 2');

    if($over_image)
     $id_image = array_shift($over_image);
    else
     return '0';
   }   
   
   if ($this->allow == 1) {
                $uri_path = __PS_BASE_URI__.($id_image).($type ? '-'.$type : '').$theme.'/'.$name.'.jpg';
            } else {
                $uri_path = _THEME_PROD_DIR_.Image::getImgFolderStatic($id_image).$id_image.($type ? '-'.$type : '').$theme.'.jpg';
            }
   
        return $this->protocol_content.Tools::getMediaServer($uri_path).$uri_path;
    }



***********************************

codigo para product.tpl en carpeta miniaturas del catalogo del theme



 onmouseover="this.src='{$link->getImageLink2($product.link_rewrite, $product.id_image , 'home_default')}';"
			  onmouseout="this.src='{$link->getImageLink($product.link_rewrite, $product.id_image, 'home_default')}';"


***************************************

Si usas otro theme que no es el CLASSIC


PUEDE QUE SALGA  un error de "undefined theme" 
Para solucionarlo copie la siguiente linea de la funcion getImageLink a getImageLink2: 
        
// legacy mode or default image
$theme = ((Shop::isFeatureActive() && file_exists(_PS_PROD_IMG_DIR_ . $ids . ($type ? '-' . $type : '') . '-' . Context::getContext()->shop->theme_name . '.jpg')) ? '-' . Context::getContext()->shop->theme_name : '');

añadir a getImageLink2 justo antes de:
$uriPath = __PS_BASE_URI__.($id_image).($type ? '-'.$type : '').$theme.'/'.$name.'.jpg';

Y LISTO DISCULPEN LAS MOLESTIAS Y NO OLVIDES DE SUSCRIBIRTE AL CANAL