PHP建立縮略圖例子

<?php define("GIF",1); define("JPG",2); define("PNG",3); /** $src_file sourse file $dest_file dest file $new_size array('width'=>?,'height'=?) $quantity the quantity of desc $method gd1.0 or gd2.0 **/ function ResizeImage($src_file="",$dest_file="",$new_size=array('width'=>100,'height'=>78),$quantity="80",$method="gd2"){ //get infomation of iamge /* 0 => width 1 => height 2 =& gt; 1 = GIF， 2 = JPG， 3 = PNG， 4 = SWF， 5 = PSD， 6 = BMP， 7 = TIFF(intel byte order)， 8 = TIFF(motorola byte order)， 9 = JPC， 10 = JP2， 11 = JPX， 12 = JB2， 13 = SWC， 14 = IFF， 15 = WBMP， 16 = XBM 3 => height="yyy" width="xxx" */ $imginfo = getimagesize($src_file); if ($imginfo == null)return false; // GD can only handle JPG & PNG images if($imginfo[2] != JPG && $imginfo[2] != PNG && $inginfo[2] != GIF && ($method == 'gd1' || $method == 'gd2')){ die("file is not be supported"); return false; } $srcWidth = $imginfo[0]; $srcHeight = $imginfo[1]; $radio=max(($srcWidth/$new_size['width']),($srcHeight/$new_size['height'])); $destWidth=(int)$srcWidth/$radio; $destHeight=(int)$srcHeight/$radio; switch ($method) { case "gd1" : if (!function_exists('imagecreatefromjpeg')) { die("PHP running on your server does not support the GD image library"); } if ($imginfo[2] == JPG) $src_img = imagecreatefromjpeg($src_file); elseif($imginfo[2] == PNG) $src_img = imagecreatefrompng($src_file); else $src_img = imagecreatefromgif($src_file); if (!$src_img){return false;} $dst_img = imagecreate($destWidth, $destHeight); imagecopyresized($dst_img, $src_img, 0, 0, 0, 0, $destWidth, (int)$destHeight, $srcWidth, $srcHeight); imagejpeg($dst_img, $dest_file, $quantity); imagedestroy($src_img); imagedestroy($dst_img); break; case "gd2" : // check if support GD2 if (!function_exists('imagecreatefromjpeg')) { die("PHP running on your server does not support the GD image library"); } if (!function_exists('imagecreatetruecolor')) { die("PHP running on your server does not support GD version 2.x, please change to GD version 1.x on your method"); } if ($imginfo[2] == JPG) $src_img = imagecreatefromjpeg($src_file); elseif($imginfo[2] == PNG) $src_img = imagecreatefrompng($src_file); else $src_img = imagecreatefromgif($src_file); if (!$src_img){return false;} $dst_img = imagecreatetruecolor($destWidth, $destHeight); imagecopyresampled($dst_img, $src_img, 0, 0, 0, 0, $destWidth, (int)$destHeight, $srcWidth, $srcHeight); imagejpeg($dst_img, $dest_file, $quantity); imagedestroy($src_img); imagedestroy($dst_img); break; } // Set mode of uploaded picture chmod($dest_file, 0755); // We check that the image is valid $imginfo = @getimagesize($dest_file); if ($imginfo == null){ @unlink($dest_file); return false; }else{ return true; } } $src_file="2.jpg"; $dest_file="22.jpg"; $new_size=array('width'=>100,'height'=>59); $quantity="100"; $method="gd2"; ResizeImage($src_file,$dest_file, $new_size,$quantity,$method); ?> 運行方式：變量名就是註釋了，不用解釋了。