php - 调整大小并保存图像? [复制]
Posted
技术标签:
【中文标题】php - 调整大小并保存图像? [复制]【英文标题】:php - resize and save an image? [duplicate] 【发布时间】:2012-06-26 22:10:59 【问题描述】:可能重复:Resize a picture to a fixed size
我正在使用以下 php 代码调整大小(宽度)并保存图像,代码运行没有错误,但图像没有调整大小。
<?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, $new_path);// save image
?>
基本上,如果图像宽度大于 700 我想将其设置为 700 吗?我做错了什么?
【问题讨论】:
您的代码没有做任何调整大小。您所做的只是覆盖 getimagesize 返回的计算值 你只是改变了内存中的宽度值,实际上并没有对图像做任何事情(除了重命名它)。 虽然是一个基本错误,但不值得一票否决 【参考方案1】:变量$image_size['0']
不是对实际图像大小的引用。
您需要计算尺寸的比率,然后使用适当的调整图像大小的函数调整它的大小,可能在 GD library 中。
首先,您必须加载图像。我会让你选择类型是什么:
$image = imagecreatefromjpeg($new_path);
$image = imagecreatefromgif($new_path);
$image = imagecreatefrompng($new_path);
现在计算比率:
$ratio = 700 / imagesx($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
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,我在这里重新创建了它:
<?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 = $new_image;
?>
【讨论】:
将图像保持在 700x500 以内:$ratio=max(700/imagesx($image),500/imagesy($image)); 你的直觉是正确的,链接现在是 404 :) 我可以验证这个类可以完美运行!谢谢【参考方案2】:您正在设置一个变量,而不是调整图像大小。我挖了一些旧功能,您需要传递图像对象,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,但可以完成工作。
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($image);
【讨论】:
创建$image
有什么意义,因为它没有在其余代码中使用?之后你只能使用$image_p
和$source
。
没有意义,你也不应该取消任何 IMO 设置。这是很久以前的事了,所以我不记得我为什么这样做了:)
如果您已经将文件上传到服务器,则应将所有 $imgObject['tmp_name'] 代码更改为 $imgObject。这对我有用,非常感谢,你拯救了我的夜晚;)【参考方案3】:
您应该使用 imagecopyresampled 函数复制/移动图像,该函数是 GD 扩展的一部分。
【讨论】:
以上是关于php - 调整大小并保存图像? [复制]的主要内容,如果未能解决你的问题,请参考以下文章