PHP 图片验证码

<?php
header("Pragma: no-cache");
header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate");
session_start();
unset ($_SESSION['validate']);

$strnum = 8; //产生密码的位数
$str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; //显示的字符范围

$font_file = 'Fregne Myriad v2.ttf';//指定字体文件

$disturbpiont = true; //是否显示干扰素
$disturbpiontnum = 600; //干扰素的点的数目
$disturbline = true; //是否有干扰条
$disturblinenum = 8; //干扰条的数目

$l = strlen($str);

$randStr = array ();
$validate;
for ($i = 0; $i < $strnum; ++ $i) {
    $randStr[$i] = $str[rand(0, $l)];
}

for ($i = 0; $i < $strnum; ++ $i) {
    if ($randStr[$i] == '')
        $randStr[$i] = '*';
    $validate = $validate . $randStr[$i];
}


function RgbToHsv($R, $G, $B) {
    $tmp = min($R, $G);
    $min = min($tmp, $B);
    $tmp = max($R, $G);
    $max = max($tmp, $B);
    $V = $max;
    $delta = $max - $min;

    if ($max != 0)
        $S = $delta / $max; // s
    else {
        $S = 0;
        return;
    }
    if ($R == $max)
        $H = ($G - $B) / $delta; // between yellow & magenta
    else
        if ($G == $max)
            $H = 2 + ($B - $R) / $delta; // between cyan & yellow
    else
        $H = 4 + ($R - $G) / $delta; // between magenta & cyan

    $H *= 60; // degrees
    if ($H < 0)
        $H += 360;
    return array (
        $H,
        $S,
        $V
    );
}

function HsvToRgb($H, $S, $V) {
    if ($S == 0) {
        // achromatic (grey)
        $R = $G = $B = $V;
        return;
    }

    $H /= 60; // sector 0 to 5
    $i = floor($H);
    $f = $H - $i; // factorial part of h
    $p = $V * (1 - $S);
    $q = $V * (1 - $S * $f);
    $t = $V * (1 - $S * (1 - $f));

    switch ($i) {
        case 0 :
            $R = $V;
            $G = $t;
            $B = $p;
            break;
        case 1 :
            $R = $q;
            $G = $V;
            $B = $p;
            break;
        case 2 :
            $R = $p;
            $G = $V;
            $B = $t;
            break;
        case 3 :
            $R = $p;
            $G = $q;
            $B = $V;
            break;
        case 4 :
            $R = $t;
            $G = $p;
            $B = $V;
            break;
        default : // case 5:
            $R = $V;
            $G = $p;
            $B = $q;
            break;
    }
    return array (
        $R,
        $G,
        $B
    );
}

$size = 30;
$width = $size * $strnum +10;
$height = $size +10;
$degrees = array ();
for ($i = 0; $i < $strnum; ++ $i) {
    $degrees[$i] = rand(0, 35);
} // 生成数字旋转角度

for ($i = 0; $i < $strnum; ++ $i) {
    if (rand() % 2);
    else
        $degrees[$i] = - $degrees[$i];
}

$image = imagecreatetruecolor($size, $size); // 数字图片画布
$validatepic = imagecreatetruecolor($width, $height); // 最终验证码画布
$back = imagecolorallocate($image, 255, 255, 255); // 背景色
$border = imagecolorallocate($image, 0, 0, 0); // 边框
imagefilledrectangle($validatepic, 0, 0, $width, $height, $back); // 画出背景色

// 数字颜色
for ($i = 0; $i < $strnum; ++ $i) {
    // 考虑为使字符容易看清使用颜色较暗的颜色
    $temp = RgbToHsv(rand(0, 255), rand(0, 255), rand(0, 255));

    if ($temp[2] > 60)
        $temp[2] = 60;

    $temp = HsvToRgb($temp[0], $temp[1], $temp[2]);
    $textcolor[$i] = imagecolorallocate($image, $temp[0], $temp[1], $temp[2]);
}

for ($i = 0; $i < $disturbpiontnum && $disturbpiont; ++ $i) //加入干扰象素
    {
    $randpixelcolor = ImageColorallocate($validatepic, rand(0, 255), rand(0, 255), rand(0, 255));
    imagesetpixel($validatepic, rand(1, $width -1), rand(1, $height -1), $randpixelcolor);
}

// 干扰线使用颜色较明亮的颜色
$temp = RgbToHsv(rand(0, 255), rand(0, 255), rand(0, 255));

if ($temp[2] < 200)
    $temp[2] = 255;

$temp = HsvToRgb($temp[0], $temp[1], $temp[2]);
$randlinecolor = imagecolorallocate($image, $temp[0], $temp[1], $temp[2]);

// 画干扰线
for ($i = 0; $i < $disturblinenum && $disturbline; $i++)
    imageline($validatepic, rand(1, 239), rand(1, 39), rand(1, 239), rand(1, 39), $randpixelcolor);

for ($i = 0; $i < $strnum; ++ $i) {
    $image = imagecreatetruecolor($size, $size); // 刷新画板
    imagefilledrectangle($image, 0, 0, $size, $size, $back); // 画出背景色
    imagefttext($image, 13, 0, 5, 20, $textcolor[$i], $font_file, $randStr[$i]);
    $image = imagerotate($image, $degrees[$i], $back);
    imagecolortransparent($image, $back);
    imagecopymerge($validatepic, $image, 5 + 30 * $i, 5, 0, 0, imagesx($image), imagesy($image), 100);
}
imagerectangle($validatepic, 0, 0, $width -1, $height -1, $border); // 画出边框

header('Content-type: image/png');
imagepng($validatepic);
imagedestroy($validatepic);
imagedestroy($image);
$_SESSION['code'] = $validate;//将验证码存入session，如果实际应用，请md5.
?>

<?php
header("Pragma: no-cache");
header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate");
session_start();
unset ($_SESSION['validate']);

$strnum = 8; //产生密码的位数
$str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; //显示的字符范围

$font_file = 'Fregne Myriad v2.ttf';//指定字体文件

$disturbpiont = true; //是否显示干扰素
$disturbpiontnum = 600; //干扰素的点的数目
$disturbline = true; //是否有干扰条
$disturblinenum = 8; //干扰条的数目

$l = strlen($str);

$randStr = array ();
$validate;
for ($i = 0; $i < $strnum; ++ $i) {
	$randStr[$i] = $str[rand(0, $l)];
}

for ($i = 0; $i < $strnum; ++ $i) {
	if ($randStr[$i] == '')
		$randStr[$i] = '*';
	$validate = $validate . $randStr[$i];
}


function RgbToHsv($R, $G, $B) {
	$tmp = min($R, $G);
	$min = min($tmp, $B);
	$tmp = max($R, $G);
	$max = max($tmp, $B);
	$V = $max;
	$delta = $max - $min;

	if ($max != 0)
		$S = $delta / $max; // s
	else {
		$S = 0;
		return;
	}
	if ($R == $max)
		$H = ($G - $B) / $delta; // between yellow & magenta
	else
		if ($G == $max)
			$H = 2 + ($B - $R) / $delta; // between cyan & yellow
	else
		$H = 4 + ($R - $G) / $delta; // between magenta & cyan

	$H *= 60; // degrees
	if ($H < 0)
		$H += 360;
	return array (
		$H,
		$S,
		$V
	);
}

function HsvToRgb($H, $S, $V) {
	if ($S == 0) {
		// achromatic (grey)
		$R = $G = $B = $V;
		return;
	}

	$H /= 60; // sector 0 to 5
	$i = floor($H);
	$f = $H - $i; // factorial part of h
	$p = $V * (1 - $S);
	$q = $V * (1 - $S * $f);
	$t = $V * (1 - $S * (1 - $f));

	switch ($i) {
		case 0 :
			$R = $V;
			$G = $t;
			$B = $p;
			break;
		case 1 :
			$R = $q;
			$G = $V;
			$B = $p;
			break;
		case 2 :
			$R = $p;
			$G = $V;
			$B = $t;
			break;
		case 3 :
			$R = $p;
			$G = $q;
			$B = $V;
			break;
		case 4 :
			$R = $t;
			$G = $p;
			$B = $V;
			break;
		default : // case 5:
			$R = $V;
			$G = $p;
			$B = $q;
			break;
	}
	return array (
		$R,
		$G,
		$B
	);
}

$size = 30;
$width = $size * $strnum +10;
$height = $size +10;
$degrees = array ();
for ($i = 0; $i < $strnum; ++ $i) {
	$degrees[$i] = rand(0, 35);
} // 生成数字旋转角度

for ($i = 0; $i < $strnum; ++ $i) {
	if (rand() % 2);
	else
		$degrees[$i] = - $degrees[$i];
}

$image = imagecreatetruecolor($size, $size); // 数字图片画布
$validatepic = imagecreatetruecolor($width, $height); // 最终验证码画布
$back = imagecolorallocate($image, 255, 255, 255); // 背景色
$border = imagecolorallocate($image, 0, 0, 0); // 边框
imagefilledrectangle($validatepic, 0, 0, $width, $height, $back); // 画出背景色

// 数字颜色
for ($i = 0; $i < $strnum; ++ $i) {
	// 考虑为使字符容易看清使用颜色较暗的颜色
	$temp = RgbToHsv(rand(0, 255), rand(0, 255), rand(0, 255));

	if ($temp[2] > 60)
		$temp[2] = 60;

	$temp = HsvToRgb($temp[0], $temp[1], $temp[2]);
	$textcolor[$i] = imagecolorallocate($image, $temp[0], $temp[1], $temp[2]);
}

for ($i = 0; $i < $disturbpiontnum && $disturbpiont; ++ $i) //加入干扰象素
	{
	$randpixelcolor = ImageColorallocate($validatepic, rand(0, 255), rand(0, 255), rand(0, 255));
	imagesetpixel($validatepic, rand(1, $width -1), rand(1, $height -1), $randpixelcolor);
}

// 干扰线使用颜色较明亮的颜色
$temp = RgbToHsv(rand(0, 255), rand(0, 255), rand(0, 255));

if ($temp[2] < 200)
	$temp[2] = 255;

$temp = HsvToRgb($temp[0], $temp[1], $temp[2]);
$randlinecolor = imagecolorallocate($image, $temp[0], $temp[1], $temp[2]);

// 画干扰线
for ($i = 0; $i < $disturblinenum && $disturbline; $i++)
	imageline($validatepic, rand(1, 239), rand(1, 39), rand(1, 239), rand(1, 39), $randpixelcolor);

for ($i = 0; $i < $strnum; ++ $i) {
	$image = imagecreatetruecolor($size, $size); // 刷新画板
	imagefilledrectangle($image, 0, 0, $size, $size, $back); // 画出背景色 
	imagefttext($image, 13, 0, 5, 20, $textcolor[$i], $font_file, $randStr[$i]);
	$image = imagerotate($image, $degrees[$i], $back);
	imagecolortransparent($image, $back);
	imagecopymerge($validatepic, $image, 5 + 30 * $i, 5, 0, 0, imagesx($image), imagesy($image), 100);
}
imagerectangle($validatepic, 0, 0, $width -1, $height -1, $border); // 画出边框

header('Content-type: image/png');
imagepng($validatepic);
imagedestroy($validatepic);
imagedestroy($image);
$_SESSION['code'] = $validate;//将验证码存入session，如果实际应用，请md5.
?>

 字体文件和该文件放在同一目录下即可，如果不是请设置

$font_file

$font_file

需要设置背景颜色请修改

$back = imagecolorallocate($image, 255, 255, 255); // 背景色

$back = imagecolorallocate($image, 255, 255, 255); // 背景色

显示图框的大小会随着设置显示的字符数变化。使用起来还是比较方便的。