php 等比例缩小图片

function imageresize2($width, $height, $targetw, $targeth)
{
  $percentage = 1;
  if (($width > $targetw) || ($height > $targeth))
  {
 $width_diff = $width - $targetw;
 $height_diff = $height - $targeth;
 
 if ($width_diff >= $height_diff)
 {
  $percentage = ($targetw / $width);
 }
 else
 {
  $percentage = ($targeth / $height);
 }
  }
 //gets the new value and applies the percentage, then rounds the value
 $width = round($width * $percentage);
 $height = round($height * $percentage);
 $resize[0] = $width;
 $resize[1] = $height;
 return $resize;
}

//方法二

if (!$max_width)  
  $max_width = 240;  
if (!$max_height)  
  $max_height = 200;  
 
$size = getimagesize($image);  
$width = $size[0];  
$height = $size[1];  
 
$x_ratio = $max_width / $width;  
$y_ratio = $max_height / $height;  
 
if ( ($width <= $max_width) && ($height <= $max_height) ) {  
  $tn_width = $width;  
  $tn_height = $height;  
}  
else if (($x_ratio * $height) < $max_height) {  
  $tn_height = ceil($x_ratio * $height);  
  $tn_width = $max_width;  
}  
else {  
  $tn_width = ceil($y_ratio * $width);  
  $tn_height = $max_height;  
}  
 
$src = imagecreatefrompng($image);  
$dst = imagecreate($tn_width,$tn_height);  
imagecopyresized($dst, $src, 0, 0, 0, 0,  
    $tn_width,$tn_height,$width,$height);  
header("content-type: image/png");  
imagepng($dst, null, -1);  
imagedestroy($src);  
imagedestroy($dst);  

//方法三

/*
函数原型如下：
参数说明：
$oldwidth:原图片宽度
$oldheight:原图片高度
$imgwidth:缩小或放大的图片宽度
$imgheight:缩小或放大的图片高度
返回：wwww.111cn.net
数组：arraysize ,其中索引为：width 和height 即：arraysize['width']、arraysize['height']
*/
function getimgsize($oldwidth,$oldheight,$imgwidth,$imgheight)
{
//$oldwidth设置的宽度，$oldheight设置的高度，$imgwidth图片的宽度，$imgheight图片的高度；

//单元格装得能装得进图片，则按图片的真实大小显示；
if($imgwidth<=$oldwidth&&$imgheight<=$oldheight)
{
$arraysize=array('width'=>$imgwidth,'height'=>$imgheight);
return $arraysize;
}
else
{
$suoxiaowidth=$imgwidth-$oldwidth;
$suoxiaoheight=$imgheight-$oldheight;
$suoxiaoheightper=$suoxiaoheight/$imgheight;
$suoxiaowidthper=$suoxiaowidth/$imgwidth;
if($suoxiaoheightper>=$suoxiaowidthper)
{
//单元格高度为准；
$aftersuoxiaowidth=$imgwidth*(1-$suoxiaoheightper);
$arraysize=array('width'=>$aftersuoxiaowidth,'height'=>$oldheight);
return $arraysize;
}
else
{
//单元格宽度为准；
$aftersuoxiaoheight=$imgheight*(1-$suoxiaowidthper);
$arraysize=array('width'=>$oldwidth,'height'=>$aftersuoxiaoheight);
return $arraysize;
}
}
}

//adv0.jpg就是背景图片,注意函数与图片格式对应  
$im = imagecreatefromjpeg('/www/law/images/demo/adv0.jpg');   
$font_color = imagecolorallocate ($im, 0, 250, 10); //这是文字颜色，绿色  
 
$text = "张三的博客";                               //文字内容  
 
$font_file = "/www/font/hyi_xkj.ttf";               //字体的linux绝对路径  
 
//26：字体， 0 是角度， 10，36是坐标， $font_color是文字色， font是字体，  文本是填入的文字  
imagettftext($im, 26,0, 10, 36, $font_color ,$font_file, $text);  往图片插入文字  
 
// output image  
header ('content-type: image/png');                 //即便是从jpg拷贝的图片，也能以png输出，  
imagepng ($im);  
// clean up  
imagedestroy($im);

public final class imageutils {
public imageutils() {

}

public final static string getpressimgpath(){
return applicationcontext.getrealpath("/template/data/util/shuiyin.gif");
}

/**
* 把图片印刷到图片上
* @param pressimg -- 水印文件
* @param targetimg -- 目标文件
* @param x
* @param y
*/
public final static void pressimage(string pressimg, string targetimg, int x, int y) {
try {
file _file = new file(targetimg);
image src = imageio.read(_file);
int wideth = src.getwidth(null);
int height = src.getheight(null);
bufferedimage image = new bufferedimage(wideth, height,
bufferedimage.type_int_rgb);
graphics g = image.creategraphics();
g.drawimage(src, 0, 0, wideth, height, null);

// 水印文件
file _filebiao = new file(pressimg);
image src_biao = imageio.read(_filebiao);
int wideth_biao = src_biao.getwidth(null);
int height_biao = src_biao.getheight(null);
g.drawimage(src_biao, wideth - wideth_biao - x, height - height_biao -y, wideth_biao,
height_biao, null);
// /
g.dispose();
fileoutputstream out = new fileoutputstream(targetimg);
jpegimageencoder encoder = jpegcodec.createjpegencoder(out);
encoder.encode(image);
out.close();
} catch (exception e) {
e.printstacktrace();
}
}

/**
* 打印文字水印图片
* @param presstext --文字
* @param targetimg -- 目标图片
* @param fontname -- 字体名
* @param fontstyle -- 字体样式
* @param color -- 字体颜色
* @param fontsize -- 字体大小
* @param x -- 偏移量
* @param y
*/

public static void presstext(string presstext, string targetimg, string fontname,int fontstyle, int color, int fontsize, int x, int y) {
try {
file _file = new file(targetimg);
image src = imageio.read(_file);
int wideth = src.getwidth(null);
int height = src.getheight(null);
bufferedimage image = new bufferedimage(wideth, height,
bufferedimage.type_int_rgb);
graphics g = image.creategraphics();
g.drawimage(src, 0, 0, wideth, height, null);
// string s=www.111cn.net;
g.setcolor(color.red);
g.setfont(new font(fontname, fontstyle, fontsize));

g.drawstring(presstext, wideth - fontsize - x, height - fontsize/2 - y);
g.dispose();
fileoutputstream out = new fileoutputstream(targetimg);
jpegimageencoder encoder = jpegcodec.createjpegencoder(out);
encoder.encode(image);
out.close();
} catch (exception e) {
system.out.println(e);
}
}

public static void main(string[] args) {
pressimage("c:/shuiyin/shuiyin.gif", "c:/shuiyin/dsc02342.jpg", 20 ,20);
}
}

function str2pic ($string,$source,$destination="",$f,$fontsize=10,$shadowcolor="#ffffff",$f,$x=10,$y=10) {  
 //header('content-type:image/png');
    $pi=pathinfo($source);
    $pie=$pi[extension];#获取扩展名
    if(eregi("jpg|jpeg",$pie))$im=@imagecreatefromjpeg($source);
    if(eregi("gif",$pie))$im=@imagecreatefromgif($source);
    if(eregi("png",$pie))$im=@imagecreatefrompng($source);
    $col1=hex2dec($shadowcolor);#阴影颜色
    $col2=hex2dec($fontcolor);#字体颜色
    $col1=imagecolorallocate($im,$col1[0],$col1[1],$col1[2]);
    $col2=imagecolorallocate($im,$col2[0],$col2[1],$col2[2]);
    imagettftext($im,$fontsize,0,$y+1,$x+1,$col1,$fonturl,$string);
    imagettftext($im,$fontsize,0,$y,$x,$col2,$fonturl,$string);
    imagejpeg($im);
    if($destination)imagejpeg($im,$destination);
    imagedestroy($im);
}

function hex2dec($hexcolror) {#十六进制颜色转换成10进制颜色
    preg_match_all("/([0-f]){2,2}/i",$hexcolror,$matches);
    if(count($matches[0])==3){
    $rr=hexdec($matches[0][0]);
    $gg=hexdec($matches[0][1]);
    $bb=hexdec($matches[0][2]);
    }
    return array($rr,$gg,$bb);
}
?>
<?php
str2pic("[url=http://www.111cn.net]www.111cn.net","winter.jpg","winter2.jpg","simhei.ttf",10,"ffffff","330099",10,10[/url]);
?>

session_start();
session_register('safecode');
$type = 'gif';
$width= 40;
$height= 16;
header("content-type: image/".$type);
srand((double)microtime()*1000000);
$randval = randstr(4,"");
if($type!='gif' && function_exists('imagecreatetruecolor')){
     $im = @imagecreatetruecolor($width,$height);
}else{
     $im = @imagecreate($width,$height);
}
     $r = array(225,211,255,223);
     $g = array(225,236,237,215);
     $b = array(225,236,166,125);

     $key = rand(0,3);
 
     $backcolor = imagecolorallocate($im,$r[$key],$g[$key],$b[$key]);//背景色（随机）
     $bordercolor = imagecolorallocate($im, 0, 0, 0);//边框色
     $pointcolor = imagecolorallocate($im, 255, 170, 255);//点颜色

     @imagefilledrectangle($im, 0, 0, $width - 1, $height - 1, $backcolor);//背景位置
     @imagerectangle($im, 0, 0, $width-1, $height-1, $bordercolor); //边框位置
     $stringcolor = imagecolorallocate($im, 255,51,153);

     for($i=0;$i<=100;$i++){
           $pointx = rand(2,$width-2);
           $pointy = rand(2,$height-2);
           @imagesetpixel($im, $pointx, $pointy, $pointcolor);
     }

     @imagestring($im, 3, 5, 1, $randval, $stringcolor);
     $imagefun='image'.$type;
     $imagefun($im);
     @imagedestroy($im);
     $_session['safecode'] = $randval;
//产生随机字符串
function randstr($len=6,$format='all') {
           switch($format) {
                 case 'all':
                 $chars='abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789www.111cn.net'; break;
                 case 'char':
                 $chars='abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz'; break;
                 case 'number':
                 $chars='0123456789'; break;
                 default :
                 $chars='abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789';
                 break;
           }
     $string="";
     while(strlen($string)<$len)
     $string.=substr($chars,(mt_rand()%strlen($chars)),1);
     return $string;
}

//调用此页面，如果下面的式子成立，则生成验证码图片
if($_get["action"]=="verifycode")
{
    rand_create();
}
//验证码图片生成
function rand_create()
{
    //通知浏览器将要输出png图片
    header("content-type: image/png");
    //准备好随机数发生器种子 
    srand((double)microtime()*1000000);
    //准备图片的相关参数  
    $im = imagecreate(62,20);
    $black = imagecolorallocate($im, 0,0,0);  //rgb黑色标识符
    $white = imagecolorallocate($im, 255,255,255); //rgb白色标识符
    $gray = imagecolorallocate($im, 200,200,200); //rgb灰色标识符
    //开始作图    
    imagefill($im,0,0,$gray);
    while(($randval=rand()%100000)<10000);{
        $_session["login_check_num"] = $randval;
        //将四位整数验证码绘入图片 
        imagestring($im, 5, 10, 3, $randval, $black);
    }
    //加入干扰象素   
    for($i=0;$i<200;$i++){
        $randcolor = imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));
        imagesetpixel($im, rand()%70 , rand()%30 , $randcolor);
    }
    //输出验证图片
    imagepng($im);
    //销毁图像标识符
    imagedestroy($im);
}
//检验验证码
function rand_check()
{
    if($_post["reg_rand"] == $_session["login_check_num"]){
        return true;
    }
    else{
        exit("验证码输入错误");
    }
}