PHP图像大小调整 [英] PHP Image Resizing

问题描述

我有一个将文件上传到服务器的脚本，并将文件名添加到数据库中，但是我想要在上传之前限制图像的最大尺寸。所以，如果我上传的图片是1000 x 500，它将被限制，但仍然保持它的尺寸，将被更改为200 x 100，但300 x 300的图像将被限制为200 x 200元/ b
$ b

 <？php 
 
 //这是保存图片的目录
 $ target =uploads /; 
 $ target = $ target。 basename（$ _FILES ['photo'] ['name']）; 
 
 //这将从表单
 $ name = $ _ POST ['name']; 
 $ pic =（$ _ FILES ['photo'] ['name']）; 
 
 //连接到你的数据库
 mysql_connect（hostname，username，password）或die（mysql_error（））; 
 mysql_select_db（database）或die（mysql_error（））; 
 $ b $ //将信息写入数据库
 mysql_query（INSERT INTO`table`（name，photo）VALUES（'$ name'，'$ pic'））; 
 $ b $ //将照片写入服务器
 if（move_uploaded_file（$ _ FILES ['photo'] ['tmp_name']，$ target））
 {
 
 //告诉你它是否全部ok 
回显The file。 basename（$ _FILES ['uploadedfile'] ['name']）。 已上传; 
} 
 else {
 
 //给出错误，如果不是
则回显抱歉，上传文件时出现问题。 
} 
？> 
  

感谢您的帮助

解决方案

据我所知，您不能在上载之前调整图片大小。 （我可能是错的！）然而，当你上传图像时，它会进入一个临时文件。您可以调整临时图像大小，并将调整大小的图像复制到最终目的地。

这段代码是根据FliquidStudios的代码片段调整的：。

由于（看起来）你想保持宽度不变，你不需要做很多比率测试。

更新：

您应该可以简单地使用它来代替您的原始代码。大部分是不变的。

 <？php 
 
 //调整图片大小给定的像素宽度。 
 //使用BMP，PNG，JPEG和GIF 
 // $文件被覆盖
函数fit_image_file_to_width（$ file，$ w，$ mime ='image / jpeg'）{
 list（$ width，$ height）= getimagesize（$ file）; 
 $ newwidth = $ w; 
 $ newheight = $ w * $ height / $ width; 
 
 switch（$ mime）{
 case'image / jpeg'：
 $ src = imagecreatefromjpeg（$ file）; 
 break; 
 case'image / png'; 
 $ src = imagecreatefrompng（$ file）; 
 break; 
 case'image / bmp'; 
 $ src = imagecreatefromwbmp（$ file）; 
 break; 
 case'image / gif'; 
 $ src = imagecreatefromgif（$ file）; 
 break; 
} 
 
 $ dst = imagecreatetruecolor（$ newwidth，$ newheight）; 
 imagecopyresampled（$ dst，$ src，0，0，0，$ newwidth，$ newheight，$ width，$ height）; 
 
 switch（$ mime）{
 case'image / jpeg'：
 imagejpeg（$ dst，$ file）; 
 break; 
 case'image / png'; 
 imagealphablending（$ dst，false）; 
 imagesavealpha（$ dst，true）; 
 imagepng（$ dst，$ file）; 
 break; 
 case'image / bmp'; 
 imagewbmp（$ dst，$ file）; 
 break; 
 case'image / gif'; 
 imagegif（$ dst，$ file）; 
 break; 
} 
 
 imagedestroy（$ dst）; 
 
 
 // init文件变量
 $ pic = $ _FILES ['photo'] ['name']; 
 $ target ='uploads /'。 basename（$ _FILES ['photo'] ['name']）; 
 $ temp_name = $ _FILES ['photo'] ['tmp_name']; 
 $ type = $ _FILES [photo] [type]; 
 
 //连接到你的数据库
 mysql_connect（hostname，username，password）或die（mysql_error（））; 
 mysql_select_db（database）或die（mysql_error（））; 
 
 //获取表单数据
 $ name = mysql_real_escape_string（isset（$ _ POST ['name']）？$ _POST ['name']：'No name'）; 
 $ b $ //将信息写入数据库
 mysql_query（INSERT INTO`table`（name，photo）VALUES（'$ name'，'$ pic'））; 
 
 //在tmp中调整图片大小
 fit_image_file_to_width（$ temp_name，200，$ type）; 
 
 //将照片写入服务器
 if（move_uploaded_file（$ temp_name，$ target））{
 
 //告诉你它是否全部ok 
回显文件。 basename（$ _FILES ['photo'] ['name']）。 已上传; 
 $ b} else {
 
 //给出错误，如果不是
回显对不起，上传文件时出现问题。 
 
} 
 
？> 
  

I've got a script that uploads files to the server as well as adds the filename to a database, but what I'd like to do it restrict the maximum dimensions of the image before uploading. So if I upload an image that is 1000 x 500 it will be restricted but still keep it's dimensions and will be changed to 200 x 100, but an image that is 300 x 300 will be restricted to 200 x 200

    <?php 

     //This is the directory where images will be saved 
     $target = "uploads/"; 
     $target = $target . basename( $_FILES['photo']['name']); 

     //This gets all the other information from the form 
     $name=$_POST['name']; 
     $pic=($_FILES['photo']['name']); 

     // Connects to your Database 
     mysql_connect("hostname", "username", "password") or die(mysql_error()) ; 
     mysql_select_db("database") or die(mysql_error()) ; 

     //Writes the information to the database 
     mysql_query("INSERT INTO `table` (name, photo) VALUES ('$name','$pic')") ; 

     //Writes the photo to the server 
     if(move_uploaded_file($_FILES['photo']['tmp_name'], $target)) 
     { 

     //Tells you if its all ok 
     echo "The file ". basename( $_FILES['uploadedfile']['name']). " has been uploaded"; 
     } 
     else { 

     //Gives and error if its not 
     echo "Sorry, there was a problem uploading your file."; 
     } 
     ?> 

Thanks for your help

解决方案

To my knowledge, you can’t resize the image before uploading it. (I could be wrong!) However, when you upload the image it goes into a temporary file. You can resize the temporary image and copy the resized image to its final destination.

This code was adapted from a snippet at FliquidStudios: Resizing images in PHP with GD and Imagick.

Since (it seems) you want to keep the width constant, you don’t really need to do a lot of ratio tests.

Update:

You should be able to simply use this in place of your original code. Most of it is unchanged.

<?php

// resizes an image to fit a given width in pixels.
// works with BMP, PNG, JPEG, and GIF
// $file is overwritten
function fit_image_file_to_width($file, $w, $mime = 'image/jpeg') {
    list($width, $height) = getimagesize($file);
    $newwidth = $w;
    $newheight = $w * $height / $width;

    switch ($mime) {
        case 'image/jpeg':
            $src = imagecreatefromjpeg($file);
            break;
        case 'image/png';
            $src = imagecreatefrompng($file);
            break;
        case 'image/bmp';
            $src = imagecreatefromwbmp($file);
            break;
        case 'image/gif';
            $src = imagecreatefromgif($file);
            break;
    }

    $dst = imagecreatetruecolor($newwidth, $newheight);
    imagecopyresampled($dst, $src, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);

    switch ($mime) {
        case 'image/jpeg':
            imagejpeg($dst, $file);
            break;
        case 'image/png';
            imagealphablending($dst, false);
            imagesavealpha($dst, true);
            imagepng($dst, $file);
            break;
        case 'image/bmp';
            imagewbmp($dst, $file);
            break;
        case 'image/gif';
            imagegif($dst, $file);
            break;
    }

    imagedestroy($dst);
}

// init file vars
$pic  = $_FILES['photo']['name'];
$target = 'uploads/' . basename( $_FILES['photo']['name']);
$temp_name = $_FILES['photo']['tmp_name'];
$type = $_FILES["photo"]["type"];

// Connects to your Database 
mysql_connect("hostname", "username", "password") or die(mysql_error()) ; 
mysql_select_db("database") or die(mysql_error()) ; 

// get form data
$name = mysql_real_escape_string(isset($_POST['name']) ? $_POST['name'] : 'No name');

//Writes the information to the database 
mysql_query("INSERT INTO `table` (name, photo) VALUES ('$name','$pic')") ; 

// resize the image in the tmp directorys
fit_image_file_to_width($temp_name, 200, $type);

//Writes the photo to the server
if(move_uploaded_file($temp_name, $target)) {

    //Tells you if its all ok 
    echo "The file ". basename( $_FILES['photo']['name'] ). " has been uploaded"; 

} else {

    //Gives and error if its not 
    echo "Sorry, there was a problem uploading your file."; 

}

?>

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