PHP利用GD库画图和生成验证码图片_PHP教程

print_r(gd_info());

Array
(
    [GD Version] => bundled (2.0.34 compatible)
    [FreeType Support] => 1
    [FreeType Linkage] => with freetype
    [T1Lib Support] => 1
    [GIF Read Support] => 1
    [GIF Create Support] => 1
    [JPG Support] => 1
    [PNG Support] => 1
    [WBMP Support] => 1
    [XPM Support] => 
    [XBM Support] => 1
    [JIS-mapped Japanese Font Support] => 
)

<!--?php
header(Content-type: image/jpeg);

$width = 400;   //宽，高
$height = 400;  

$image = imagecreate($width, $height); //第一步：创建空白图像

$white = imagecolorallocate($image, 0, 0, 0);  //第一次对 imagecolorallocate() 的调用会给基于调色板的图像填充背景色，即用 imagecreate() 建立的图像。 

$green = imagecolorallocate($image, 0, 255, 0); //第二步：为图像分配颜色

imageline($image, 0, 20, 400, 20, $green);  //第三步：画线
imagerectangle($image,100,40,300,100,$green);  //画矩形
imagearc($image, 200, 150, 90, 90, 0, 360, $green); //画圆
imagestring($image, 14, 100, 240, PHP is NiuBi HongHong!, $green); //写字符串

$str=abcdefghjklmnpqrstuvwxyz23456789;
$randstr = substr(str_shuffle($str), 0,4);
imagestring($image, 14, 100, 260, $randstr, $green); //验证码

imagettftext($image, 14, 0, 100, 300, $green, &#39;./MSJHBD.TTF&#39;, 中文vsEnglish);  //中文验证

// imagejpeg($image,&#39;./test.jpg&#39;);   //在当前路径下保存图片为test.jpg
imagejpeg($image);  //第四步：不加文件名，直接输出到网页     

imagedestroy($image);   //第五步：销毁，回收资源
?-->

<!--?php
header(Content-type: image/png);

$width = 300;   //原图宽，高
$height = 210;  

$thumb_width = (int)$width/2;
$thumb_height = (int)$height/2;


$dst = imagecreate($thumb_width,$thumb_height); //创建缩略图画布

$gray = imagecolorallocate($dst, 100, 100, 100);


$src = imagecreatefrompng(&#39;./me.png&#39;); //读取原图

//把原图copy到缩略图画布上
imagecopyresampled($dst, $src, 0, 0, 0, 0, $thumb_width, $thumb_height, $width, $height); 

imagepng($dst,&#39;./me_thumb.png&#39;);

imagedestroy($dst);
imagedestroy($src);
?-->