php 验证码生成程序[可自动判断php gd库]

php 验证码生成程序[可自动判断php gd库]
function ShowKey()
{
$key=strtolower(domake_password(4));
$set=esetcookie("checkkey",$key);
 //是否支持gd库
if (function_exists("imagejpeg")) {
   header ("Content-type: image/jpeg");
   $img=imagecreate(69,20);
   $black=imagecolorallocate($img,255,255,255);
   $gray=imagecolorallocate($img,102,102,102);
   imagefill($img,0,0,$gray);
   imagestring($img,3,14,3,$key,$black);
   imagejpeg($img);
   imagedestroy($img);
}
elseif (function_exists("imagegif")) {
   header ("Content-type: image/gif");
   $img=imagecreate(69,20);
   $black=imagecolorallocate($img,255,255,255);
   $gray=imagecolorallocate($img,102,102,102);
   imagefill($img,0,0,$gray);
   imagestring($img,3,14,3,$key,$black);
   imagegif($img);
   imagedestroy($img);
}
elseif (function_exists("imagepng")) {
 header ("Content-type: image/png");
   $img=imagecreate(69,20);
   $black=imagecolorallocate($img,255,255,255);
   $gray=imagecolorallocate($img,102,102,102);
   imagefill($img,0,0,$gray);
   imagestring($img,3,14,3,$key,$black);
   imagepng($img);
   imagedestroy($img);
}
elseif (function_exists("imagewbmp")) {
 header ("Content-type: image/vnd.wap.wbmp");
   $img=imagecreate(69,20);
   $black=imagecolorallocate($img,255,255,255);
   $gray=imagecolorallocate($img,102,102,102);
   imagefill($img,0,0,$gray);
   imagestring($img,3,14,3,$key,$black);
   imagewbmp($img);
   imagedestroy($img);
}
else {
 $set=esetcookie("checkkey","ebak");
 @include("class/functions.php");
 echo ReadFiletext("images/ebak.jpg");
}
}
ShowKey();

php imagecreate实例教程

描述
资源imagecreate（$width，$height）
imagecreate（）返回一个图像标识符代表了指定大小的空白图像。

我们建议使用imagecreatetruecolor（）。

看个
<?php
header("Content-type: image/png");
$im = @imagecreate(110, 20)
    or die("Cannot Initialize new GD image stream");
$background_color = imagecolorallocate($im, 0, 0, 0);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5,  "A Simple Text String", $text_color);
imagepng($im);
imagedestroy($im);
?>

如果您可以访问gd.h（很少在一个共享的主机），您可以修改GD_RESOLUTION并给它所需的价值。

该解决方案，我发现直接操纵的JPEG头字节。
我希望此示例代码将帮助别人，因为我花了5挖掘推测离开系统I小时，没有其他选择。

<?php
header('Content-Disposition: attachment; filename="myimg.jpg"');
header('Cache-Control: private');
$dst    = imagecreatetruecolor(300, 300); /*this creates a 300x300 pixels image*/
ob_start(); /*don't send the output to the browser since we'll need to manipulate it*/
ImageJpeg($dst);
$img = ob_get_contents();
ob_end_clean();

//byte #14 in jpeg sets the resolution type: 0=none, 1=pixels per inch, 2=pixels per cm
//bytes 15-16 sets X resolution
//bytes 17-18 sets Y resolution
$img = substr_replace($img, pack('cnn',1,300,300),13,5);

echo $img;

?>

文件在其文件类型，并返回假的负载如果失败
<?php
function imagecreatefromfile($path, $user_functions = false)
{
    $info = @getimagesize($path);
   
    if(!$info)
    {
        return false;
    }
   
    $functions = array(
        IMAGETYPE_GIF => 'imagecreatefromgif',
        IMAGETYPE_JPEG => 'imagecreatefromjpeg',
        IMAGETYPE_PNG => 'imagecreatefrompng',
        IMAGETYPE_WBMP => 'imagecreatefromwbmp',
        IMAGETYPE_XBM => 'imagecreatefromwxbm',
        );
   
    if($user_functions)
    {
        $functions[IMAGETYPE_BMP] = 'imagecreatefrombmp';
    }
   
    if(!$functions[$info[2]])
    {
        return false;
    }
   
    if(!function_exists($functions[$info[2]]))
    {
        return false;
    }
   
    return $functions[$info[2]]($path);
}
?>

php 图片下载程序

function displayimg($image)
 {
  $image = './upload/'.imgdecode($image);
  //echo $image;exit;
  if (file_exists($image))
  {
   $info = getimagesize($image);
   header("Content-type:$info[mime]");
   switch ($info[2])
   {
    case 1:  $cimage = imagecreatefromgif($image);
       imagegif($cimage);
       imagedestroy($cimage);
       break;
    case 2:  $cimage = imagecreatefromjpeg($image);
       imagejpeg($cimage);
       imagedestroy($cimage);
       break;
    case 3:  $cimage = imagecreatefrompng($image);
       imagepng($cimage);
       imagedestroy($cimage);
       break;
    case 6:  $cimage = imagecreatefromwbmp($image);
       imagewbmp($cimage);
       imagedestroy($cimage);
       break;
   }
   echo $simage;
  }
  else
  {
   header("HTTP/1.0 404 Not Found");
  }
 }

php 创建图片教程,我们在编程时经常会看到用php 写图片，验证码等

<?php

$height = 300;

$width = 300;

$im = ImageCreateTrueColor($width, $height);

$white = ImageColorAllocate ($im, 255, 255, 255);

$blue = ImageColorAllocate ($im, 0, 0, 64);

ImageFill($im, 0, 0, $blue);

//ImageLine($im, 0, 0, $width, $height, $white);

ImageString($im, 10, 100, 120, 'Hello,PHP', $white);

Header ('Content-type: image/png');

ImagePng($im);

ImageDestroy($im);

?>

php 图处理函数实例教程, 图片处理，php,图片函数

<?php
//公用函数

//把角度转换为弧度
function deg2Arc($degrees) {
return($degrees * (pi()/180.0));
}

//RGB
function getRGB($color){
  $R=($color>>16) & 0xff;
  $G=($color>>8) & 0xff;
  $B=($color) & 0xff;
  return (array($R,$G,$B));
}

// 取得在椭圆心为（0，0）的椭圆上 x,y点的值
function pie_point($deg,$va,$vb){
$x= cos(deg2Arc($deg)) * $va;
$y= sin(deg2Arc($deg)) * $vb;
return (array($x, $y));
}

//3D饼图类

class chart{

var $a; //椭圆长半轴
var $b; //椭圆短半轴
var $DataArray;  //每个扇形的数据
var $ColorArray; //每个扇形的颜色 要求按照十六进制书写但前面不加0x
//为边缘及阴影为黑色

function chart($pa=100,$pb=60,$sData="100,200,300,400,500,300", $sColor="ee00ff,dd0000,cccccc,ccff00,00ccff,ccff00")
{
    $this->a=$pa;
    $this->b=$pb;
    $this->DataArray=split(",",$sData);
    $this->ColorArray=split(",",$sColor);
}

function setA($v){
    $this->a=$v;
}

function getA(){
    return $this->a;
}

function setB($v){
    $this->b=$v; 
}

function getB(){
    return $this->b;
}

function setDataArray($v){
    $this->DataArray=split(",",$v);
}

function getDataArray($v){
    return $this->DataArray;
}

function setColorArray($v){
    $this->ColorArray=split(",",$v);
}

function getColorArray(){
    return  $this->ColorArray;
}

 
function  DrawPie(){
    $image=imagecreate($this->a*2+40,$this->b*2+40);
    $PieCenterX=$this->a+10;
    $PieCenterY=$this->b+10;
    $DoubleA=$this->a*2;
    $DoubleB=$this->b*2;
    list($R,$G,$B)=getRGB(0);
    $colorBorder=imagecolorallocate($image,$R,$G,$B);
    $DataNumber=count($this->DataArray);
    
    //$DataTotal
    for($i=0;$i<$DataNumber;$i++)      $DataTotal+=$this->DataArray[$i]; //算出数据和
    
    //填充背境
    imagefill($image, 0, 0, imagecolorallocate($image, 0xFF, 0xFF, 0xFF));

    /*
    ** 画每一个扇形
    */
    $Degrees = 0;
    for($i = 0; $i < $DataNumber; $i++){
        $StartDegrees = round($Degrees);
        $Degrees += (($this->DataArray[$i]/$DataTotal)*360);
        $EndDegrees = round($Degrees);
        $percent = number_format($this->DataArray[$i]/$DataTotal*100, 1); 
        list($R,$G,$B)=getRGB(hexdec($this->ColorArray[$i]));
        $CurrentColor=imagecolorallocate($image,$R,$G,$B);
        if ($R>60 and $R<256)            $R=$R-60;
        if ($G>60 and $G<256)            $G=$G-60;
        if ($B>60 and $B<256)            $B=$B-60;
        $CurrentDarkColor=imagecolorallocate($image,$R,$G,$B);
        //画扇形弧
        imagearc($image,$PieCenterX,$PieCenterY,$DoubleA,$DoubleB,$StartDegrees,$EndDegrees,$CurrentColor);
        //画直线
        list($ArcX, $ArcY) = pie_point($StartDegrees , $this->a , $this->b);
        imageline($image,$PieCenterX,$PieCenterY,floor($PieCenterX + $ArcX),floor($PieCenterY + $ArcY),$CurrentColor);
        //画直线
        list($ArcX, $ArcY) = pie_point($EndDegrees,$this->a , $this->b);
        imageline($image,$PieCenterX,$PieCenterY,ceil($PieCenterX + $ArcX),ceil($PieCenterY + $ArcY),$CurrentColor);
        //填充扇形
        $MidPoint = round((($EndDegrees - $StartDegrees)/2) + $StartDegrees);
        list($ArcX, $ArcY) = Pie_point($MidPoint, $this->a*3/4 , $this->b*3/4);
        
        imagefilltoborder($image,floor($PieCenterX + $ArcX),floor($PieCenterY + $ArcY), $CurrentColor,$CurrentColor);
        imagestring($image,2,floor($PieCenterX + $ArcX-5),floor($PieCenterY + $ArcY-5),$percent."%",$colorBorder);

        //画阴影
        if ($StartDegrees>=0 and $StartDegrees<=180){
           if($EndDegrees<=180){    
               for($k = 1; $k < 15; $k++)
                imagearc($image,$PieCenterX, $PieCenterY+$k,$DoubleA, $DoubleB, $StartDegrees, $EndDegrees, $CurrentDarkColor);
           }else{
               for($k = 1; $k < 15; $k++)
                imagearc($image,$PieCenterX, $PieCenterY+$k,$DoubleA, $DoubleB, $StartDegrees, 180, $CurrentDarkColor);
           }

        }
   }
        
    /*到此脚本已经生了一幅图像了
    **现在需要的是把它发到浏览器上，重要的一点是要将标头发给浏览器，让它知道是一个GIF文件。不然的话你只能看到一堆奇怪的乱码
    */ 
    //输出生成的图片    
    header("Content-type: image/gif");
    imagegif($image);
    imagedestroy($image);
}//End drawPie()
}//End class

//实现

$objp = new chart();
$objp->DrawPie();
?>