PHP源码: 生成条行码状登陆验证码

<?php
function UPCAbarcode($code) {
 $lw = 1.5; //宽度
 $hi = 50; //高度
 $Lencode = array('0001101','0011001','0010011','0111101','0100011',
 '0110001','0101111','0111011','0110111','0001011');
 $Rencode = array('1110010','1100110','1101100','1000010','1011100',
 '1001110','1010000','1000100','1001000','1110100');
 $ends = '101'; $center = '01010';
 /* UPC-A Must be 11 digits, we compute the checksum. */
 if ( strlen($code) != 11 ) { die("UPC-A Must be 11 digits."); }
 /* Compute the EAN-13 Checksum digit */
 $ncode = '0'.$code;
 $even = 0; $odd = 0;
 for ($x=0;$x<12;$x++) {
  if ($x % 2) { $odd += $ncode[$x]; } else { $even += $ncode[$x]; }
 }
 $code.=(10 - (($odd * 3 + $even) % 10)) % 10;
 /* Create the bar encoding using a binary string */
 $bars=$ends;
 $bars.=$Lencode[$code[0]];
 for($x=1;$x<6;$x++) {
  $bars.=$Lencode[$code[$x]];
 }
 $bars.=$center;
 for($x=6;$x<12;$x++) {
  $bars.=$Rencode[$code[$x]];
 }
 $bars.=$ends;
 /* Generate the Barcode Image */
 $img = ImageCreate($lw*95+30,$hi+30);
 $fg = ImageColorAllocate($img, 0, 0, 0); //字体颜色
 $bg = ImageColorAllocate($img, 255, 255, 255); //背景颜色
 ImageFilledRectangle($img, 0, 0, $lw*95+30, $hi+30, $bg);
 $shift=10;
 for ($x=0;$x<strlen($bars);$x++) {
  if (($x<10) || ($x>=45 && $x<50) || ($x >=85)) { $sh=10; }
  else { $sh=0; }
  if ($bars[$x] == '1') { $color = $fg; } else { $color = $bg; }
  ImageFilledRectangle($img, ($x*$lw)+15,5,($x+1)*$lw+14,$hi+5+$sh,$color);
 }
 /* Add the Human Readable Label */
 ImageString($img,4,5,$hi-5,$code[0],$fg);
 for ($x=0;$x<5;$x++) {
  ImageString($img,5,$lw*(13+$x*6)+15,$hi+5,$code[$x+1],$fg);
  ImageString($img,5,$lw*(53+$x*6)+15,$hi+5,$code[$x+6],$fg);
 }
 ImageString($img,4,$lw*95+17,$hi-5,$code[11],$fg);
 /* Output the Header and Content. */
 header("Content-Type: image/png");
 ImagePNG($img);
}

UPCAbarcode('65228901237');

?>