php数字验证码

<?php

session_start();

//生成验证码图片

Header("Content-type: image/PNG");

srand((double)microtime()*1000000);

$im = imagecreate(62,20);

$black = ImageColorAllocate($im, 69,120,239);

$white = ImageColorAllocate($im, 0,0,0);

$gray = ImageColorAllocate($im, 200,200,200);

imagefill($im,68,30,$gray);

while(($authnum=rand()%100000)<10000);

//将五位整数验证码绘入图片

imagestring($im, 5, 10, 3, $authnum, $white);

for($i=0;$i<200;$i++) //加入干扰象素

{

$randcolor = ImageColorallocate($im,rand(0,255),rand(0,255),rand(0,255));

imagesetpixel($im, rand()%70 , rand()%30 , $randcolor);

}
ImagePNG($im);
ImageDestroy($im);
$_SESSION['SESSION_VALIDATE_CODE'] = $authnum.'';

?>



$txt="memory";
  $im = imagecreatetruecolor(400,30);
  $white = ImageColorAllocate($im, 255,255,255);
  $black = ImageColorAllocate($im, 0,0,0);

  // Replace path by your own font path
  imagestring($im,1,10,10,$txt,$black);
  //imagettftext($im, 20, 0, 10, 20, $black, "font.ttf","Testing...");
  header("Content-type:image/jpeg");
  imagejpeg($im);
//  imagedestroy($im);