用PHP实现登陆验证码(类似条行码状)-PHP教程,PHP应用

<?php

function upcabarcode($code) {

$lw = 2; $hi = 100;

$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);

$bg = imagecolorallocate($img, 255, 255, 255);

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(12345678901);

?>