php图像处理中的等比例缩放

<?php$img = imagecreatefromjpeg('1.jpg');//打开一个新图片文件//获得文件信息,宽,高,类型list($width,$height,$type) = getimagesize('1.jpg');$new_width = 150;$new_height = 150;//等比例缩放算法if($width < $height){$new_width = ($new_height / $height) * $width;}else{$new_height = ($new_width / $width) * $height;}//创建新图像$new = imagecreatetruecolor($new_width, $new_height);imagecopyresampled($new,$img,0,0,0,0,$new_width,$new_height,$width,$height);//高清方式header('Content-Type:image/jpeg');//编码imagejpeg($new);//输出图像imagedestroy($new)//销毁资源句柄?>

可实现高清等比例缩放图片效果。