get_list_thumbnail 썸네일이미지를 최상단으로 지정하려고 수정중인데 잘 먹히지가 않습니다.

$thumb_width = 280;
$thumb_height = 200;

$thumb = get_list_thumbnail($board['bo_table'], $list[$i]['wr_id'], $thumb_width, $thumb_height, false, true,'top');

function get_list_thumbnail($bo_table, $wr_id, $thumb_width, $thumb_height, $is_create=false, $is_crop=true, $crop_mode='top', $is_sharpen=false, $um_value='80/0.5/3')

...

function thumbnail($filename, $source_path, $target_path, $thumb_width, $thumb_height, $is_create, $is_crop=true, $crop_mode='top', $is_sharpen=false, $um_value='80/0.5/3')

...

        if($is_crop) {
            switch($crop_mode)
            {
                case 'top':
                    if($size[1] / $size[0] >= $ratio) {
                        $src_h = round($src_w * $ratio);
                        $src_y = round(($size[1] - $src_h) / 2);
                    } else {
                        $src_w = round($size[1] / $ratio);
                        $src_x = round(($size[0] - $src_w) / 2);
                    }
                    break;
                default:
                    if($size[1] / $size[0] >= $ratio) {
                        $src_h = round($src_w * $ratio);
                    } else {
                        $src_w = round($size[1] / $ratio);
                    }
                    break;
            }

            $dst = imagecreatetruecolor($dst_w, $dst_h);