php - 调整大小并保存图像？

Question

可能重复：
Resize a picture to a fixed size

我使用下面的PHP代码来调整（宽度），并保存图像，该代码工作没有错误，但图像没有得到调整大小。

<?php 
$old_path = "users_images/".$name.".".$type; 
    $new_path = "main_images/".$name.".".$type; 
    $image_size = getimagesize($new_path); 
    if($image_size['0'] > 700){ 
     $image_size['0'] = 700; 
     } 
     rename($old_path, $new_path);// save image 

?> 

基本上如果图像宽度大于700我想将它设置为700？我做错了什么？

Answer 1

您应该使用作为GD扩展的一部分的imagecopyresampled函数来复制/移动图像。

Answer 2

变量$image_size['0']不是对实际图像大小的引用。

您需要计算尺寸的比例，然后使用调整图像大小的适当功能重新调整它的大小，可能在GD library。

首先，您必须加载图像。我会让你选择是什么类型：

$image = imagecreatefromjpeg($new_path); 
$image = imagecreatefromgif($new_path); 
$image = imagecreatefrompng($new_path); 

现在计算的比例：

$ratio = 700/imagesx($image); // 700 for the width you want... 
           // imagesx() to determine the current width 

获取缩放高度：

$height = imagesy($image) * $ratio; // imagesy() to determine the current height 

做实际调整大小：

$new_image = imagecreatetruecolor($width, $height); 
imagecopyresampled($new_image, $image, 0, 0, 0, 0, $width, $height, imagesx($image), imagesy($image)); 
$image = $new_image; // $image has now been replaced with the resized one. 

---

我找到了simple class for resizing images。为了防止链接腐烂，我在这里重新创建它：

<?php 

/* 
* File: SimpleImage.php 
* Author: Simon Jarvis 
* Copyright: 2006 Simon Jarvis 
* Date: 08/11/06 
* Link: http://www.white-hat-web-design.co.uk/articles/php-image-resizing.php 
* 
* This program is free software; you can redistribute it and/or 
* modify it under the terms of the GNU General Public License 
* as published by the Free Software Foundation; either version 2 
* of the License, or (at your option) any later version. 
* 
* This program is distributed in the hope that it will be useful, 
* but WITHOUT ANY WARRANTY; without even the implied warranty of 
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
* GNU General Public License for more details: 
* http://www.gnu.org/licenses/gpl.html 
* 
*/ 

class SimpleImage { 

    var $image; 
    var $image_type; 

    function load($filename) { 

     $image_info = getimagesize($filename); 
     $this->image_type = $image_info[2]; 
     if($this->image_type == IMAGETYPE_JPEG) { 

     $this->image = imagecreatefromjpeg($filename); 
     } elseif($this->image_type == IMAGETYPE_GIF) { 

     $this->image = imagecreatefromgif($filename); 
     } elseif($this->image_type == IMAGETYPE_PNG) { 

     $this->image = imagecreatefrompng($filename); 
     } 
    } 
    function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) { 

     if($image_type == IMAGETYPE_JPEG) { 
     imagejpeg($this->image,$filename,$compression); 
     } elseif($image_type == IMAGETYPE_GIF) { 

     imagegif($this->image,$filename); 
     } elseif($image_type == IMAGETYPE_PNG) { 

     imagepng($this->image,$filename); 
     } 
     if($permissions != null) { 

     chmod($filename,$permissions); 
     } 
    } 
    function output($image_type=IMAGETYPE_JPEG) { 

     if($image_type == IMAGETYPE_JPEG) { 
     imagejpeg($this->image); 
     } elseif($image_type == IMAGETYPE_GIF) { 

     imagegif($this->image); 
     } elseif($image_type == IMAGETYPE_PNG) { 

     imagepng($this->image); 
     } 
    } 
    function getWidth() { 

     return imagesx($this->image); 
    } 
    function getHeight() { 

     return imagesy($this->image); 
    } 
    function resizeToHeight($height) { 

     $ratio = $height/$this->getHeight(); 
     $width = $this->getWidth() * $ratio; 
     $this->resize($width,$height); 
    } 

    function resizeToWidth($width) { 
     $ratio = $width/$this->getWidth(); 
     $height = $this->getheight() * $ratio; 
     $this->resize($width,$height); 
    } 

    function scale($scale) { 
     $width = $this->getWidth() * $scale/100; 
     $height = $this->getheight() * $scale/100; 
     $this->resize($width,$height); 
    } 

    function resize($width,$height) { 
     $new_image = imagecreatetruecolor($width, $height); 
     imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight()); 
     $this->image = $new_image; 
    }  

} 
?> 

Answer 3

您正在设置一个变量，而不是调整图像的大小。我挖了一些旧功能，你需要传递图像对象，保存路径，图像名称，最大高度，最大宽度和质量。这不是最好的功能，但它完成了工作。

function resizeImage($imgObject, $savePath, $imgName, $imgMaxWidth, $imgMaxHeight, $imgQuality) 
{ 
    $source = imagecreatefromjpeg($imgObject['tmp_name']); 
    list($imgWidth, $imgHeight) = getimagesize($imgObject['tmp_name']); 
    $imgAspectRatio = $imgWidth/$imgHeight; 
    if ($imgMaxWidth/$imgMaxHeight > $imgAspectRatio) 
    { 
     $imgMaxWidth = $imgMaxHeight * $imgAspectRatio; 
    } 
    else 
    { 
     $imgMaxHeight = $imgMaxWidth/$imgAspectRatio; 
    } 
    $image_p = imagecreatetruecolor($imgMaxWidth, $imgMaxHeight); 
    $image = imagecreatefromjpeg($imgObject['tmp_name']); 
    imagecopyresampled($image_p, $source, 0, 0, 0, 0, $imgMaxWidth, $imgMaxHeight, $imgWidth, $imgHeight); 
    imagejpeg($image_p, $savePath . $imgName, $imgQuality); 
    unset($imgObject); 
    unset($source); 
    unset($image_p); 
    unset($image); 
}