php 截图，缩图，水印

function imageWaterMark($groundImage,$waterPos=0,$waterImage="",$waterText="MYWEB",$textFont=5,$textColor="#FF0000",$w_alpha="")
{
    $isWaterImage = FALSE;
    $formatMsg = "暂不支持该文件格式，请用图片处理软件将图片转换为GIF、JPG、PNG格式。";

    //读取水印文件
    if(!empty($waterImage) && file_exists($waterImage))
    {
        $isWaterImage = TRUE;
        $water_info = getimagesize($waterImage);
        $water_w    = $water_info[0];//取得水印图片的宽
        $water_h    = $water_info[1];//取得水印图片的高

        switch($water_info[2])//取得水印图片的格式
        {
            case 1:$water_im = imagecreatefromgif($waterImage);break;
            case 2:$water_im = imagecreatefromjpeg($waterImage);break;
            case 3:$water_im = imagecreatefrompng($waterImage);break;
            default:die($formatMsg);
        }
    }

    //读取背景图片
    if(!empty($groundImage) && file_exists($groundImage))
    {
        $ground_info = getimagesize($groundImage);
        $ground_w    = $ground_info[0];//取得背景图片的宽
        $ground_h    = $ground_info[1];//取得背景图片的高

        switch($ground_info[2])//取得背景图片的格式
        {
            case 1:$ground_im = imagecreatefromgif($groundImage);break;
            case 2:$ground_im = imagecreatefromjpeg($groundImage);break;
            case 3:$ground_im = imagecreatefrompng($groundImage);break;
            default:die($formatMsg);
        }
    }
    else
    {
        die("需要加水印的图片不存在！");
    }

    //水印位置
    if($isWaterImage)//图片水印
    {
        $w = $water_w;
        $h = $water_h;
        $label = "图片的";
    }
    else//文字水印
    {
        $temp = imagettfbbox(ceil($textFont*2.5),0,"./cour.ttf",$waterText);//取得使用 TrueType 字体的文本的范围
        $w = $temp[2] - $temp[6];
        $h = $temp[3] - $temp[7];
        unset($temp);
        $label = "文字区域";
    }
    if( ($ground_w<$w) || ($ground_h<$h) )
    {
        //echo "需要加水印的图片的长度或宽度比水印".$label."还小，无法生成水印！";
        return;
    }
    switch($waterPos)
    {
        case 0://随机
            $posX = rand(0,($ground_w - $w));
            $posY = rand(0,($ground_h - $h));
            break;
        case 1://1为顶端居左
            $posX = 0;
            $posY = 0;
            break;
        case 2://2为顶端居中
            $posX = ($ground_w - $w) / 2;
            $posY = 0;
            break;
        case 3://3为顶端居右
            $posX = $ground_w - $w;
            $posY = 0;
            break;
        case 4://4为中部居左
            $posX = 0;
            $posY = ($ground_h - $h) / 2;
            break;
        case 5://5为中部居中
            $posX = ($ground_w - $w) / 2;
            $posY = ($ground_h - $h) / 2;
            break;
        case 6://6为中部居右
            $posX = $ground_w - $w;
            $posY = ($ground_h - $h) / 2;
            break;
        case 7://7为底端居左
            $posX = 0;
            $posY = $ground_h - $h;
            break;
        case 8://8为底端居中
            $posX = ($ground_w - $w) / 2;
            $posY = $ground_h - $h;
            break;
        case 9://9为底端居右
            $posX = $ground_w - $w;
            $posY = $ground_h - $h;
            break;
        default://随机
            $posX = rand(0,($ground_w - $w));
            $posY = rand(0,($ground_h - $h));
            break;     
    }

    //设定图像的混色模式
    imagealphablending($ground_im, true);

    if($isWaterImage)//图片水印
    {
        
        if(!$w_alpha)
        {
            global $webdb;
            $w_alpha=$webdb[waterAlpha];
        }
        $w_alpha>0 || $w_alpha=100;
        imagecopymerge($ground_im, $water_im, $posX, $posY, 0, 0, $water_w,$water_h,$w_alpha);
    }
    else//文字水印
    {
        if( !empty($textColor) && (strlen($textColor)==7) )
        {
            $R = hexdec(substr($textColor,1,2));
            $G = hexdec(substr($textColor,3,2));
            $B = hexdec(substr($textColor,5));
        }
        else
        {
            die("水印文字颜色格式不正确！");
        }
        imagestring ( $ground_im, $textFont, $posX, $posY, $waterText, imagecolorallocate($ground_im, $R, $G, $B));         
    }

    //生成水印后的图片 //
    @unlink($groundImage);
    
    if(function_exists("Imagegif")){

        switch($ground_info[2])//取得背景图片的格式
        {
            case 1:imagegif($ground_im,$groundImage);break;
            case 2:imagejpeg($ground_im,$groundImage);break;
            case 3:imagepng($ground_im,$groundImage);break;
            default:die($errorMsg);
        }

    }elseif(function_exists("imagejpeg")){
        imagejpeg($ground_im,$groundImage);
    }else{
        imagepng($ground_im,$groundImage);
    }

    //释放内存
    if(isset($water_info)) unset($water_info);
    if(isset($water_im)) imagedestroy($water_im);
    unset($ground_info);
    imagedestroy($ground_im);
}

/**
*把图片缩小
**/
function ResizeImage($oldpic,$newpic,$maxwidth=800,$maxheight=600){
    if( eregi('.jpg',$oldpic) ){
         $im = imagecreatefromjpeg($oldpic);
    }elseif( eregi('.png',$oldpic) ){
         $im = imagecreatefrompng($oldpic);
    }elseif( eregi('.gif',$oldpic) ){
        $im = imagecreatefromgif($oldpic);
    }else{
        //die("图片格式不对$oldpic");
    }
    $width = imagesx($im);
    $height = imagesy($im);
    if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
        if($maxwidth && $width > $maxwidth){
            $widthratio = $maxwidth/$width;
            $RESIZEWIDTH=true;
        }
        if($maxheight && $height > $maxheight){
            $heightratio = $maxheight/$height;
            $RESIZEHEIGHT=true;
        }
        if($RESIZEWIDTH && $RESIZEHEIGHT){
            if($widthratio < $heightratio){
                $ratio = $widthratio;
            }else{
                $ratio = $heightratio;
            }
        }elseif($RESIZEWIDTH){
            $ratio = $widthratio;
        }elseif($RESIZEHEIGHT){
            $ratio = $heightratio;
        }
        $newwidth = $width * $ratio;
        $newheight = $height * $ratio;
        if(function_exists("imagecopyresampled")){
              $newim = imagecreatetruecolor($newwidth, $newheight);
              imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
        }else{
            $newim = imagecreate($newwidth, $newheight);
            //imagepstext($newim,'tryr','10','12','000000','000000',0,0,5,5,1,1);
            imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
        }
        ImageJpeg ($newim,$newpic);
        ImageDestroy ($newim);
    }else{
        ImageJpeg ($im,$newpic);
    }
    ImageDestroy ($im);
}
//原图,处理过的图,坐标原点X,坐标原点Y,最终图宽,最终图高,末坐标X,末坐标Y,原图缩放情况,是否自动取值
function cutimg($srcimgurl,$endimgurl,$x,$y,$endimg_w,$endimg_h,$border_w,$border_h,$scale=100,$fix=0){
    $path = dirname ($endimgurl);
    if (!is_dir($path)) {
        if(!@mkdir ($path, 0777)){
            showerr("{$path} 此目录不能创建,文件创建失败");
        }
    }
    $ground_info = getimagesize($srcimgurl);
    switch($ground_info[2]){
        case 1:$im = imagecreatefromgif($srcimgurl);break;
        case 2:$im = imagecreatefromjpeg($srcimgurl);break;
        case 3:$im = imagecreatefrompng($srcimgurl);break;
        default:die("图片格式不允许$srcimgurl");
    }
    if($fix){//方便截取头像的一部分
        if($ground_info[0]<$ground_info[1]){
            $border_w=$ground_info[0];
            $border_h=$endimg_h*$ground_info[0]/$endimg_w;
        }elseif($ground_info[0]>$ground_info[1]){
            $border_h=$ground_info[1];
            $border_w=$endimg_w*$ground_info[1]/$endimg_h;
        }else{
            $border_w=$ground_info[0];
            $border_h=$ground_info[1];
        }
    }
    $newim = imagecreatetruecolor($endimg_w, $endimg_h);
    $x=($x*100)/$scale;
    $y=($y*100)/$scale;
    $border_width=($border_w*100)/$scale;
    $border_height=($border_h*100)/$scale;
    imagecopyresampled($newim, $im, 0,0, $x,$y, $endimg_w, $endimg_h, $border_width, $border_height );
    if(function_exists("Imagegif")){
        switch($ground_info[2]){
            case 1:imagegif($newim,$endimgurl);break;
            case 2:imagejpeg($newim,$endimgurl);break;
            case 3:imagepng($newim,$endimgurl);break;
            default:die("errorMsg");
        }
    }elseif(function_exists("imagejpeg")){
        imagejpeg($newim,$endimgurl);
    }else{
        imagepng($newim,$endimgurl);
    }
    ImageDestroy ($newim);
    ImageDestroy ($im);
}

function gdfillcolor($srcFile,$dstFile,$dstW,$dstH){
    @ImageAlphaBlending($srcFile, true);
    $picdata = GetImageSize($srcFile);
    switch ($picdata[2]) {
        case 1:
            $im = @ImageCreateFromGIF($srcFile);
            break;
        case 2:
            $im = @imageCreateFromJpeg($srcFile);
            break;
        case 3:
            $im = @ImageCreateFromPNG($srcFile);
            break;
        case 6:
            $im = @ImageCreateFromWbmp($srcFile);
            break;
    }
    $srcW=ImageSX($im);
    $srcH=ImageSY($im);
    $dstX=0;
    $dstY=0;
    if ($srcW*$dstH>$srcH*$dstW) {
        $fdstH=round($srcH*$dstW/$srcW);
        $dstY=floor(($dstH-$fdstH)/2);
        $fdstW=$dstW;
    }else{
        $fdstW=round($srcW*$dstH/$srcH);
        $dstX=floor(($dstW-$fdstW)/2);
        $fdstH=$dstH;
    }
    $dstX=($dstX<0)?0:$dstX;
    $dstY=($dstX<0)?0:$dstY;
    $dstX=($dstX>($dstW/2))?floor($dstW/2):$dstX;
    $dstY=($dstY>($dstH/2))?floor($dstH/s):$dstY;


    $ni=imagecreatetruecolor($dstW,$dstH);
    $black = ImageColorAllocate($ni, 255,255,255);
    $white = ImageColorAllocate($ni, 255,255,255);
    imagefilledrectangle($ni,0,0,$dstW,$dstH,$black);// 填充剩余背景色
    if(function_exists("imagecopyresampled")){// 改变图片大小
        imagecopyresampled($ni,$im,$dstX,$dstY,0,0,$fdstW,$fdstH,$srcW,$srcH);
    }else{
        imagecopyresized($ni, $im, $dstX, $dstY, 0, 0, $fdstW, $fdstH, $srcW, $srcH);
    }
    if(function_exists("Imagegif")){
        Imagegif($ni,$dstFile); // 输出到文件
    }else{
         ImageJpeg ($ni,$dstFile);
    }
    imagedestroy($im);// 清理内存
    imagedestroy($ni);
}