Bueno, viendo que no aparece nadies por aquí... dejo el script
para los novatos como yo. Esto hará que se muestre la imagen Captcha en versiones php4
Código PHP:
<?php
/**
* PHPcaptcha
* @author Myokram
* 29/03/08
*/
/**
* Para usar esta clase:
* Visita http://www.phperu.net/phpcaptcha
*
*/
class Captcha {
var $codigo;
var $refCodigos;
var $refFondos;
var $refFuentes;
var $fuentes = array();
var $refFiltro = true;
var $refColor = array(0, 0, 0);
var $refTamano = 25;
var $refLineas = true;
var $refGradoDificultad = 8;
var $refNLineas = 20;
var $refCLineas = false;
var $refLongitud = 6;
var $refCaracteres = array();
var $fondo;
var $texto;
var $ancho;
var $alto;
var $captcha;
function __construct() {
}
function checkSession() {
if(!isset($_SESSION)) {
@session_start();
return false;
}
return true;
}
function generaCaptcha($nuevo = true) {
$this->checkSession();
if(empty($this->codigo)) {
if($nuevo == false and !empty($_SESSION['phpcaptcha_codigo'])) {
$this->codigo = $_SESSION['phpcaptcha_codigo'];
} else {
$this->generarCodigo();
}
}
$this->generarFondo();
if($this->refLineas == true) {
$this->generarLineas();
}
$this->generarTexto();
$this->captcha = imagecreatetruecolor($this->ancho, $this->alto);
imagecopyresampled($this->captcha, $this->fondo, 0, 0, 0, 0, $this->ancho, $this->alto, $this->ancho, $this->alto);
imagecopymerge($this->captcha, $this->texto, 0, 0, 0, 0, $this->ancho, $this->alto, 60);
return true;
}
function verificaCaptcha($codigo, $mayus = false) {
self::checkSession();
$sc = ($mayus == true) ? $_SESSION['phpcaptcha_codigo'] : strtolower($_SESSION['phpcaptcha_codigo']);
$vc = ($mayus == true) ? $codigo : strtolower($codigo);
if(!empty($sc) and $sc == $vc) {
unset($_SESSION['phpcaptcha_codigo']);
return true;
}
return false;
}
function guardaCaptcha() {
$this->checkSession();
return $_SESSION['phpcaptcha_codigo'] = $this->codigo;
}
function muestraCaptcha() {
header("Expires: Sun, 1 Jan 2000 12:00:00 GMT");
header("Last-Modified: ".gmdate("D, d M Y H:i:s")."GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
header("Content-type: image/jpeg");
imagejpeg($this->captcha, null, 70);
exit;
}
function confCaptcha($p, $v) {
switch(strtolower($p)):
case "codigos": $this->refCodigos = $v; break;
case "fondos": $this->refFondos = $v; break;
case "fuentes": $this->refFuentes = $v; break;
case "dificultad": $this->refGradoDificultad = ((int)$v >= 1 and (int)$v <= 40) ? (int)$v : $this->refGradoDificultad; break;
case "filtro": $this->refFiltro = ($v != false) ? true : false; break;
case "lineas": $this->refLineas = ($v != false) ? true : false; break;
case "nlineas": $this->refNLineas = ((int)$v >= 1) ? (int)$v : $this->refNLineas; break;
case "clineas": $this->refCLineas = ($v != false) ? true : false; break;
case "color": $this->refColor = ($c = $this->rgbhex2rgb($v)) ? $c : array(0,0,0); break;
case "tamaño": $this->refTamano = (int)$v; break;
case "ancho": $this->ancho = (int)$v; break;
case "alto": $this->alto = (int)$v; break;
case "longitud": $this->refLongitud = ((int)$v >= 1) ? (int)$v : $this->refLongitud; break;
case "caracteres": if(is_array($v)) $this->confCaptcha("caracteres",implode("",$v)); else $this->refCaracteres = str_split($v); break;
default: return false; break;
endswitch;
return true;
}
function generarCodigo() {
if(!empty($this->refCodigos) and file_exists($this->refCodigos)) {
return $this->codigo = $this->generarCodigoArchivo();
}
return $this->codigo = $this->generarCodigoAleatorio();
}
function generarCodigoAleatorio() {
$caracteres = (count($this->refCaracteres) < 1) ? array_merge(range('a', 'z'), range(0, 9)) : $this->refCaracteres;
$n = count($caracteres);
$codigo = '';
while (strlen($codigo) < $this->refLongitud) {
$codigo .= $caracteres[mt_rand(0, $n-1)];
}
return $codigo;
}
function generarCodigoArchivo() {
$codigo = file($this->refCodigos);
$codigo = trim($codigo[array_rand($codigo)]);
return !empty($codigo) ? $codigo : $this->generarCodigoAleatorio();
}
function generarFondo() {
$this->ancho = ($this->ancho > 1) ? $this->ancho : 210;
$this->alto = ($this->alto > 1) ? $this->alto : 70;
if(!empty($this->refFondos) and is_dir($this->refFondos)) {
$res = opendir($this->refFondos);
$imagenes = array();
while($archivo = readdir($res)) {
if(!in_array(pathinfo($archivo, PATHINFO_EXTENSION), array("gif", "jpg", "png"))) {
continue;
}
$imagenes[] = $this->refFondos.'/'.$archivo;
}
closedir($res);
}
if(count($imagenes) < 1) {
$rs = imagecreate($this->ancho, $this->alto);
imagecolorallocate($rs, 255, 255, 255);
} else {
$aleat = $imagenes[array_rand($imagenes)];
$info = getimagesize($aleat);
$bg = null;
switch ($info[2]):
case 1: $bg = imagecreatefromgif($aleat); break;
case 2: $bg = imagecreatefromjpeg($aleat); break;
case 3: $bg = imagecreatefrompng($aleat); break;
endswitch;
$bg = imagerotate($bg,90*rand(1,4),-1);
$rs = imagecreatetruecolor($this->ancho, $this->alto);
imagecopyresampled($rs, $bg, 0, 0, 0, 0, $this->ancho, $this->alto, imagesx($bg), imagesy($bg));
}
return $this->fondo = ($this->refFiltro == true) ? $this->aplicarFiltro($rs) : $rs;
}
function generarLineas() {
for ($i = 0; $i < $this->refNLineas; $i++) {
if($this->refCLineas != true) {
$c = mt_rand(70, 250);
$clinea = imagecolorallocate($this->fondo, $c, $c, $c);
} else {
$clinea = imagecolorallocate($this->fondo, mt_rand(80, 250), mt_rand(80, 250), mt_rand(80, 250));
}
imageline($this->fondo, mt_rand(0, $this->ancho), mt_rand(0, $this->alto), mt_rand(0, $this->ancho), mt_rand(0, $this->alto), $clinea);
}
return;
}
function aplicarFiltro($rs, $ligero = 0) {
$extra = ($ligero == 1) ? (((int)$this->refGradoDificultad > 1) ? (int)$this->refGradoDificultad : 9 ) : rand(20, 30);
$rsf = imagecreatetruecolor($this->ancho+$extra, $this->alto+$extra);
$dstH = $this->ancho;
$srcH = $this->ancho - 2 * $extra;
$h = rand(5, 10);
for ($i = 0; $i < $this->ancho; $i++) {
$a = (sin(deg2rad(2*$i*$h))+sin(deg2rad($i*$h))) * 1.1;
imagecopyresized($rsf, $rs, $i, 0, $i, 0, $extra+$i, $dstH+$extra*$a, $extra+$i, $srcH);
}
return $rsf;
}
function generarTexto() {
$t = imagecreatetruecolor($this->ancho, $this->alto);
$fcolor = ($this->refColor[0] == 255 and $this->refColor[1] == 255 and $this->refColor[2] == 255) ? imagecolorallocate($t, 0, 0, 0) : imagecolorallocate($t, 255, 255, 255);
imagefill($t, 0, 0, $fcolor);
$tcolor = imagecolorallocate($t, $this->refColor[0], $this->refColor[1], $this->refColor[2]);
if(!empty($this->refFuentes) and is_dir($this->refFuentes)) {
$res = opendir($this->refFuentes);
$fuentes = array();
while($archivo = readdir($res)) {
if(!in_array(pathinfo($archivo, PATHINFO_EXTENSION), array("ttf"))) {
continue;
}
$fuentes[] = $this->refFuentes.'/'.$archivo;
}
closedir($res);
$this->fuentes = $fuentes;
$x = 15;
for ($i = 0; $i < strlen($this->codigo); $i++) {
imagettftext($t, $this->refTamano, rand(-30, 30), $x, $this->refTamano+rand(5, 25), $tcolor, $this->fuenteAleatoria(), $this->codigo{$i});
$x += $this->refTamano + 6;
}
} else {
$tfont = rand(3,5);
$tancho = imagefontwidth($tfont) * strlen($this->codigo);
$talto = imagefontheight($tfont);
$margen = $tancho * 0.3 + 5;
$ttexto = imagecreatetruecolor($tancho + $margen, $talto + $margen);
imagefill($ttexto, 0, 0, $fcolor); // For GD2+
$tx = $margen / 2;
$ty = $margen / 2;
imagestring($ttexto, $tfont, $tx, $ty, $this->codigo, $tcolor);
imagecopyresampled($t, $ttexto, 0, 0, 0, 0, $this->ancho, $this->alto, $tancho+$margen, $talto+$margen);
}
if ($this->refFiltro) {
$t = $this->aplicarFiltro($t, 1);
}
imagecolortransparent($t, $fcolor);
return $this->texto = $t;
}
function fuenteAleatoria() {
return $this->fuentes[array_rand($this->fuentes)];
}
function rgbhex2rgb($c) {
if(!$c) return false;
$c = trim($c);
$out = array();
if(eregi("^[0-9ABCDEFabcdef\#]+$", $c)){
$c = str_replace('#','', $c);
$l = strlen($c);
if($l != 3 and $l != 6) return false;
$out[0] = $out['r'] = ($l == 3) ? hexdec(substr($c,0,1).substr($c,0,1)) : hexdec(substr($c,0,2));
$out[1] = $out['g'] = ($l == 3) ? hexdec(substr($c,1,1).substr($c,1,1)) : hexdec(substr($c,2,2));
$out[2] = $out['b'] = ($l == 3) ? hexdec(substr($c,2,1).substr($c,2,1)) : hexdec(substr($c,4,2));
} elseif (eregi("^[0-9]+(,| |.)+[0-9]+(,| |.)+[0-9]+$", $c)){
if(eregi(",", $c)) $e = explode(",",$c);
elseif(eregi(" ", $c)) $e = explode(" ",$c);
elseif(eregi(".", $c)) $e = explode(".",$c);
else return false;
if(count($e) != 3) return false;
if(is_numeric($e[0]) and $e[0] >= 0 and $e[0] <= 255)
$out[0] = $out['r'] = intval($e[0]);
if(is_numeric($e[1]) and $e[1] >= 0 and $e[1] <= 255)
$out[1] = $out['g'] = intval($e[1]);
if(is_numeric($e[2]) and $e[2] >= 0 and $e[2] <= 255)
$out[2] = $out['b'] = intval($e[2]);
}
return (count($out) != 6) ? false : $out;
}
}
?>
Re: APORTE: Sistema de Captcha 
):
) Al usar la fuente del sistema el script ajusta el tamaño de la fuente para que entre todo el código en la imagen.
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