使用 PHP 创建 PNG 图像

Example #1 使用 PHP 创建 PNG 图像


<?php

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);

?>

本例程需要从带有 <img src="button.php?text=text"> 标签的页面调用。上述 button.php 脚本将 "text" 字符串绘制到一个图像上，在本例中图像文件为 "images/button1.png"，然后输出绘制后的图像。当你需要经常修改图像上的文字时，动态生成图像就可以省去了每次都重新制作图像的麻烦。

User Contributed Notes

viishalkumarsahu at gmail dot com 17-Dec-2016 06:24


Function to create random png images when requested for example...

<img src="create_image.php?s=008080_F_1000_200&t=Sample%20Image%20Drawn%20By%20PHP" alt="GD Library Example Image" >



here is create_image.php

<?php

$setting = isset($_GET['s']) ? $_GET['s'] : "FFF_111_100_100";

$setting = explode("_",$setting );

$img = array();



switch ($n = count($setting)) {

    case $n > 4 :

    case 3:

        $setting[3] = $setting[2];

    case 4:

        $img['width'] = (int) $setting[2];

        $img['height'] = (int) $setting[3];

    case 2:

        $img['color'] = $setting[1];

        $img['background'] = $setting[0];

        break;

    default:

        list($img['background'],$img['color'],$img['width'],$img['height']) = array('F','0',100,100);

        break;

}



$background = explode(",",hex2rgb($img['background']));

$color = explode(",",hex2rgb($img['color']));

$width = empty($img['width']) ? 100 : $img['width'];

$height = empty($img['height']) ? 100 : $img['height'];

$string = (string) isset($_GET['t']) ? $_GET['t'] : $width ."x". $height;



header("Content-Type: image/png");

$image = @imagecreate($width, $height)

    or die("Cannot Initialize new GD image stream");



$background_color = imagecolorallocate($image, $background[0], $background[1], $background[2]);

$text_color = imagecolorallocate($image, $color[0], $color[1], $color[2]);



imagestring($image, 5, 5, 5, $string, $text_color);

imagepng($image);

imagedestroy($image);



function hex2rgb($hex) {

    // Copied

   $hex = str_replace("#", "", $hex);



   switch (strlen($hex)) {

       case 1:

           $hex = $hex.$hex;

       case 2:

          $r = hexdec($hex);

          $g = hexdec($hex);

          $b = hexdec($hex);

           break;



       case 3:

          $r = hexdec(substr($hex,0,1).substr($hex,0,1));

          $g = hexdec(substr($hex,1,1).substr($hex,1,1));

          $b = hexdec(substr($hex,2,1).substr($hex,2,1));

           break;



       default:

          $r = hexdec(substr($hex,0,2));

          $g = hexdec(substr($hex,2,2));

          $b = hexdec(substr($hex,4,2));

           break;

   }



   $rgb = array($r, $g, $b);

   return implode(",", $rgb); 

}

Anonymous 22-Mar-2016 01:22


too low too hard for use !



    $fontsize = mt_rand(18,23); 

    //mt_rand(6,9): F5刷新会抖动！

    //$fontsize = 9;

Jeff 31-Mar-2015 06:59


Keep in mind that transparency is not preserved when doing what is shown in Example #1 to a PNG with transparency.