/*
* 图片加水印
* $source string 图片资源
* $target string 添加水印后的名字
* $w_pos int 水印位置 具体看代码
* $w_img string 水印图片路径
* $w_text string 显示的文字
* $w_font int 字体大小
* $w_color string 字体颜色
*/

function watermark($source, $target = '', $w_pos = '', $w_img = '', $w_text = '80shihua.com', $w_font = 10, $w_color = '#CC0000')
{
if (!$target) {
$target = $source;
}
$w_minwidth = 200;
$w_minheight = 200;
$w_quality =90;//图像质量
$w_pct = 85; //透明度
$source_info = getimagesize($source); //图片信息
$source_w = $source_info[0]; //图片宽度
$source_h = $source_info[1]; //图片高度
if ($source_w < $w_minwidth || $source_h < $w_minheight) { return false; } switch ($source_info[2]) { //图片类型 case 1: //GIF格式 $source_img = imagecreatefromgif($source); break; case 2: //JPG格式 $source_img = imagecreatefromjpeg($source); break; case 3: //PNG格式 $source_img = imagecreatefrompng($source); //imagealphablending($source_img,false); //关闭混色模式 imagesavealpha($source_img, true); //设置标记以在保存 PNG 图像时保存完整的 alpha 通道信息(与单一透明色相反) break; default: return false; } if (!empty($w_img) && file_exists($w_img)) { //水印图片有效 $ifwaterimage = 1; //标记 $water_info = getimagesize($w_img); $width = $water_info[0]; $height = $water_info[1]; switch ($water_info[2]) { case 1: $water_img = imagecreatefromgif($w_img); break; case 2: $water_img = imagecreatefromjpeg($w_img); break; case 3: $water_img = imagecreatefrompng($w_img); //imagealphablending($w_img, false); //imagesavealpha($w_img, true); break; default: return; } } else { $path = '/80shihua.ttf'; $ifwaterimage = 0; $temp = imagettfbbox(ceil($w_font * 2.5), 0, $path, $w_text); //imagettfbbox返回一个含有 8 个单元的数组表示了文本外框的四个角 $width = $temp[2] - $temp[6]; $height = $temp[3] - $temp[7]; unset($temp); } switch ($w_pos) { case 1: $wx = 5; $wy = 5; break; case 2: $wx = ($source_w - $width) / 2; $wy = 0; break; case 3: $wx = $source_w - $width; $wy = 0; break; case 4: $wx = 0; $wy = ($source_h - $height) / 2; break; case 5: $wx = ($source_w - $width) / 2; $wy = ($source_h - $height) / 2; break; case 6: $wx = $source_w - $width; $wy = ($source_h - $height) / 2; break; case 7: $wx = 0; $wy = $source_h - $height; break; case 8: $wx = ($source_w - $width) / 2; $wy = $source_h - $height; break; case 9: $wx = $source_w - ($width + 5); $wy = $source_h - ($height + 5); break; case 10: $wx = rand(0, ($source_w - $width)); $wy = rand(0, ($source_h - $height)); break; default: $wx = rand(0, ($source_w - $width)); $wy = rand(0, ($source_h - $height)); break; } if ($ifwaterimage) { if ($water_info[2] == 3) { imagecopy($source_img, $water_img, $wx, $wy, 0, 0, $width, $height); } else { imagecopymerge($source_img, $water_img, $wx, $wy, 0, 0, $width, $height, $this->w_pct);
}
} else {
if (!empty($w_color) && (strlen($w_color) == 7)) {
$r = hexdec(substr($w_color, 1, 2));
$g = hexdec(substr($w_color, 3, 2));
$b = hexdec(substr($w_color, 5));
} else {
return;
}

imagestring($source_img, $w_font, $wx, $wy, $w_text, imagecolorallocate($source_img, $r, $g, $b));
}

switch ($source_info[2]) {
case 1:
imagegif($source_img, $target);
//GIF 格式将图像输出到浏览器或文件(欲输出的图像资源, 指定输出图像的文件名)
break;
case 2:
imagejpeg($source_img, $target, $this->w_quality);
break;
case 3:
imagepng($source_img, $target);
break;
default:
return;
}
if (isset($water_info)) {
unset($water_info);
}
if (isset($water_img)) {
imagedestroy($water_img);
}
unset($source_info);
imagedestroy($source_img);
return true;
}

存在水印图片则根据图片生成水印,否则调用80shihua.ttf字体文件生成水印,水印文字可以自己指定.