PHP的生成图片或文字水印的类

ImageWatermark.php

<?php
/***********************************************************
类名：ImageWatermark
功能：用于生成图片或文字水印
WDPHP素材源码 http://www.wdphp.com
************************************************************
合成水印：
1、图像水印appendImageMark(暂不可旋转)
2、文字水印appendTextMark(汉字水印需要设置汉字字体)（可旋转）
输出水印图像：write($filename=null)
1、输出到文件：指定$filename参数为输出的文件名。
2、输出到浏览器：不指定输出文件名，则输出到浏览器.
指定水印位置：
1、指定位置类型$markPosType:(default-0)
1-top left     2-top center     3-top right
4-middle left  5-middle center  6-middle right
7-bottom left  8-bottom center  9-bottom right
0-random
2、设置具体位置setMarkPos($x,$y)，若指定具体位置，则上面的位置类型无效。
************************************************************
*/
class ImageWatermark {
    public $markPosType = 0; //水印位置，缺省为随机位置输出水印
    public $fontFile = 'arial.ttf'; //字体文件名
    public $color = '#CCCCCC'; //水印字体的颜色
    public $fontSize = 12; //水印字体大小
    public $angle = 0; //水印文字旋转的角度
    private $markPos = array();
    private $markImageFile = null, $destImageFile = null;
    private $mark_res = null, $mark_width = 0, $mark_height = 0, $mark_type = null;
    private $dest_res = null, $dest_width = 0, $dest_height = 0, $dest_type = null;
    //用目标图片作为构造函数的参数
    public function __construct($destImage) {
        if (!file_exists($destImage)) return false;
        $this->destImageFile = $destImage;
        //获取图片大小、类型
        $imageInfo = getimagesize($this->destImageFile);
        $this->dest_width = $imageInfo[0];
        $this->dest_height = $imageInfo[1];
        $this->dest_type = $imageInfo[2];
        //得到图片资源句柄
        $this->dest_res = $this->getImageResource($this->destImageFile, $this->dest_type);
    }
    public function __destruct() {
        imagedestroy($this->dest_res);
    }
    //添加文字水印
    public function appendTextMark($markText) {
        if ($markText == null) return false;
        //计算水印文本的大小
        $box = imagettfbbox($this->fontSize, $this->angle, $this->fontFile, $markText);
        $this->mark_width = $box[2] - $box[6];
        $this->mark_height = $box[3] - $box[7];
        //计算水印位置
        $pos = ($this->markPos != null) ? $this->markPos : $this->getMarkPosition($this->markPosType);
        $pos[1]+= $this->mark_height;
        //将文字打印到图片上
        $RGB = $this->colorHexRgb($this->color);
        $imageColor = imagecolorallocate($this->dest_res, $RGB[0], $RGB[1], $RGB[2]);
        imagettftext($this->dest_res, $this->fontSize, $this->angle, $pos[0], $pos[1], $imageColor, $this->fontFile, $markText);
    }
    //添加图片水印
    public function appendImageMark($markImage) {
        if (!file_exists($markImage)) return false;
        $this->markImageFile = $markImage;
        //获取水印图片大小、类型
        $imageInfo = getimagesize($this->markImageFile);
        $this->mark_width = $imageInfo[0];
        $this->mark_height = $imageInfo[1];
        $this->mark_type = $imageInfo[2];
        //得到图片资源句柄
        $this->mark_res = $this->getImageResource($this->markImageFile, $this->mark_type);
        //计算水印位置
        $pos = ($this->markPos != null) ? $this->markPos : $this->getMarkPosition($this->markPosType);
        //设置图像混色模式
        imagealphablending($this->dest_res, true);
        //复制叠加图像
        imagecopy($this->dest_res, $this->mark_res, $pos[0], $pos[1], 0, 0, $this->mark_width, $this->mark_height);
        imagedestroy($this->mark_res);
    }
    //将叠加水印后的图片写入指定文件，若不定文件名，则输出到浏览器
    public function write($filename = null) {
        $this->writeImage($this->dest_res, $filename, $this->dest_type);
    }
    //设置水印x,y坐标
    public function setMarkPos($x, $y) {
        $this->markPos[0] = $x;
        $this->markPos[1] = $y;
    }
    //将十六进制的颜色值分解成RGB形式
    private function colorHexRgb($color) {
        $color = preg_replace('/#/', '', $color);
        $R = hexdec($color[0] . $color[1]);
        $G = hexdec($color[2] . $color[3]);
        $B = hexdec($color[4] . $color[5]);
        return array(
            $R,
            $G,
            $B
        );
    }
    //计算水印位置
    private function getMarkPosition($type = 0) {
        switch ($type) {
            case 0:
                $x = rand(0, $this->dest_width - $this->mark_width);
                $y = rand(0, $this->dest_height - $this->mark_height);
                break; //random

            case 1:
                $x = 0;
                $y = 0;
                break; //topleft

            case 2:
                $x = ($this->dest_width - $this->mark_width) / 2;
                $y = 0;
                break; //topcenter

            case 3:
                $x = $this->dest_width - $this->mark_width;
                $y = 0;
                break; // topright

            case 4:
                $x = 0;
                $y = ($this->dest_height - $this->mark_height) / 2;
                break; //middleleft

            case 5:
                $x = ($this->dest_width - $this->mark_width) / 2;
                $y = ($this->dest_height - $this->mark_height) / 2;
                break; //middlecenter

            case 6:
                $x = $this->dest_width - $this->mark_width;
                $y = ($this->dest_height - $this->mark_height) / 2;
                break; //middleright

            case 7:
                $x = 0;
                $y = $this->dest_height - $this->mark_height;
                break; //bottomleft

            case 8:
                $x = ($this->dest_width - $this->mark_width) / 2;
                $y = $this->dest_height - $this->mark_height;
                break; //bottomcenter

            case 9:
                $x = $this->dest_width - $this->mark_width;
                $y = $this->dest_height - $this->mark_height;
                break; //bottomright

            default:
                $x = rand(0, $this->dest_width - $this->mark_width);
                $y = rand(0, $this->dest_height - $this->mark_height);
                break; //random

        }
        return array(
            $x,
            $y
        );
    }
    //从一个图像文件中取得图片资源标识符
    private function getImageResource($filename, $type = 0) {
        switch ($type) {
            case 1:
                return imagecreatefromgif($filename);
                break;

            case 2:
                return imagecreatefromjpeg($filename);
                break;

            case 3:
                return imagecreatefrompng($filename);
                break;
                // 以后可添加其它格式

            default:
                return null;
        }
    }
    //将图像写入文件或输出到浏览器
    private function writeImage($ImageRes, $filename = null, $type = 0) {
        switch ($type) {
            case 1:
                imagegif($ImageRes, $filename);
                break;

            case 2:
                imagejpeg($ImageRes, $filename);
                break;

            case 3:
                imagepng($ImageRes, $filename);
                break;

            default:
                return null;
        }
        return true;
    }
}
//使用示例
$markimg = new ImageWatermark('c_si.jpg');
//$markimg->setMarkPos(100,200);//如何设置setMarkPos,则markPosType无效。
$markimg->markPosType = 5;
$markimg->appendImageMark('mark.png');
$markimg->fontFile = 'STCAIYUN.TTF';
$markimg->color = '#FFFFFF';
$markimg->fontSize = 24;
$markimg->angle = 45; //设置角度时，注意水印可能旋转出目标图片之外。
$markimg->appendTextMark('汉字水印');
$markimg->write();
$markimg = null;
?>