水印 縮略圖 驗證碼類

 

class ImageTool {
    // imageInfo 分析圖片的信息
    // return array()
    public static function imageInfo($image) {
        // 判斷圖片是否存在
        if(!file_exists($image)) {
            return false;
        }

        $info = getimagesize($image);

        if($info == false) {
            return false;
        }

        // 此時info分析出來,是一個數組
        $img['width'] = $info[0];
        $img['height'] = $info[1];
        $img['ext'] = substr($info['mime'],strpos($info['mime'],'/')+1);

        return $img;
    }



    /*
        加水印功能
        parm String $dst 等操作圖片
        parm String $water 水印小圖
        parm String $save,不填則默認替換原始圖
    */
    public static function water($dst,$water,$save=NULL,$pos=2,$alpha=50) {
        // 先保證2個圖片存在
        if(!file_exists($dst) || !file_exists($water)) {
            return false;
        }


        // 首先保證水印不能比待操作圖片還大
        $dinfo = self::imageInfo($dst);
        $winfo = self::imageInfo($water);

        if($winfo['height'] > $dinfo['height'] || $winfo['width'] > $dinfo['width']) {
            return false;
        }

        // 兩張圖,讀到畫布上! 但是圖片可能是png,可能是jpeg,用什麼函數讀?
        $dfunc = 'imagecreatefrom' . $dinfo['ext'];
        $wfunc = 'imagecreatefrom' . $winfo['ext'];

        if(!function_exists($dfunc) || !function_exists($wfunc)) {
            return false;
        }


        // 動態加載函數來創建畫布
        $dim = $dfunc($dst);  // 創建待操作的畫布
        $wim = $wfunc($water);  // 創建水印畫布


        // 根據水印的位置 計算粘貼的座標
        switch($pos) {
            case 0: // 左上角
            $posx = 0;
            $posy = 0;
            break;

            case 1: // 右上角
            $posx = $dinfo['width'] - $winfo['width'];
            $posy = 0;
            break;

            case 3: // 左下角
            $posx = 0;
            $posy = $dinfo['height'] - $winfo['height'];
            break;

            default:
            $posx = $dinfo['width'] - $winfo['width'];
            $posy = $dinfo['height'] - $winfo['height'];
        }


        // 加水印
        imagecopymerge ($dim,$wim, $posx , $posy , 0 , 0 , $winfo['width'] , $winfo['height'] , $alpha);

        // 保存
        if(!$save) {
            $save = $dst;
            unlink($dst); // 刪除原圖
        }

        $createfunc = 'image' . $dinfo['ext'];
        $createfunc($dim,$save);

        imagedestroy($dim);
        imagedestroy($wim);

        return true;
    }


    /**
        thumb 生成縮略圖
        等比例縮放,兩邊留白
    **/
    public static function thumb($dst,$save=NULL,$width=200,$height=200) {
        // 首先判斷待處理的圖片存不存在
        $dinfo = self::imageInfo($dst);
        if($dinfo == false) {
            return false;
        }

        // 計算縮放比例
        $calc = min($width/$dinfo['width'], $height/$dinfo['height']);

        // 創建原始圖的畫布
        $dfunc = 'imagecreatefrom' . $dinfo['ext'];
        $dim = $dfunc($dst);

        // 創建縮略畫布
        $tim = imagecreatetruecolor($width,$height);

        // 創建白色填充縮略畫布
        $white = imagecolorallocate($tim,255,255,255);

        // 填充縮略畫布
        imagefill($tim,0,0,$white);

        // 複製並縮略
        $dwidth = (int)$dinfo['width']*$calc;
        $dheight = (int)$dinfo['height']*$calc;

        $paddingx = (int)($width - $dwidth) / 2;
        $paddingy = (int)($height - $dheight) / 2;


        imagecopyresampled($tim,$dim,$paddingx,$paddingy,0,0,$dwidth,$dheight,$dinfo['width'],$dinfo['height']);

        // 保存圖片
        if(!$save) {
            $save = $dst;
            unlink($dst);
        }

        $createfunc = 'image' . $dinfo['ext'];
        $createfunc($tim,$save);

        imagedestroy($dim);
        imagedestroy($tim);

        return true;

    }


    //寫驗證碼
    /*
        author: dabao
    */
    public static function captcha($width=50,$height=25) {
            //造畫布
            $image = imagecreatetruecolor($width,$height) ;

            //造背影色
            $gray = imagecolorallocate($image, 200, 200, 200);

            //填充背景
            imagefill($image, 0, 0, $gray);

            //造隨機字體顏色
            $color = imagecolorallocate($image, mt_rand(0, 125), mt_rand(0, 125), mt_rand(0, 125)) ;
            //造隨機線條顏色
            $color1 =imagecolorallocate($image, mt_rand(100, 125), mt_rand(100, 125), mt_rand(100, 125));
            $color2 =imagecolorallocate($image, mt_rand(100, 125), mt_rand(100, 125), mt_rand(100, 125));
            $color3 =imagecolorallocate($image, mt_rand(100, 125), mt_rand(100, 125), mt_rand(100, 125));

            //在畫布上畫線
            imageline($image, mt_rand(0, 50), mt_rand(0, 25), mt_rand(0, 50), mt_rand(0, 25), $color1) ;
            imageline($image, mt_rand(0, 50), mt_rand(0, 20), mt_rand(0, 50), mt_rand(0, 20), $color2) ;
            imageline($image, mt_rand(0, 50), mt_rand(0, 20), mt_rand(0, 50), mt_rand(0, 20), $color3) ;

            //在畫布上寫字
            $text = substr(str_shuffle('ABCDEFGHIJKMNPRSTUVWXYZabcdefghijkmnprstuvwxyz23456789'), 0,4) ;
            imagestring($image, 5, 7, 5, $text, $color) ;

            //顯示、銷燬
            header('content-type: image/jpeg');
            imagejpeg($image);
            imagedestroy($image);
    }


}