请问如何使用GD库来创建一个PNG/GIF图画？

[qqaazzqq2009]

告诉我需要什么函数、先后顺序就好了

[xuzuning]

手册上的例子
header("Content-type: image/png");
$string = $_GET['text'];
$im = imagecreatefrompng("images/button1.png");
$orange = imagecolorallocate($im, 220, 210, 60);
$px = (imagesx($im) - 7.5 * strlen($string)) / 2;
imagestring($im, 3, $px, 9, $string, $orange);
imagepng($im);
imagedestroy($im);

[CunningBoy]

PNG

<?php
$im = imagecreatefrompng("test.png");

header('Content-type: image/png');

imagepng($im);
imagedestroy($im);
?>

GIF

<?php
// Create a new image instance
$im = imagecreatetruecolor(100, 100);

// Make the background white
imagefilledrectangle($im, 0, 0, 99, 99, 0xFFFFFF);

// Draw a text string on the image
imagestring($im, 3, 40, 20, 'GD Library', 0xFFBA00);

// Output the image to browser
header('Content-type: image/gif');

imagegif($im);
imagedestroy($im);
?>