PHP Upload and Resize Image
By Brian on Jul 27, 2010 with Comments 24
Many times when you upload a image somewhere you want to resize it to different dimensions based off of a maximum width or height. Here is a simple script that does this for you, using a HTML form and a PHP script. We start with the PHP script that will run if our $_GET['do'] is set to “upload.” Then we include the HTML form that has three inputs (max width, max height, image file).
Use the Upload and Resize Demo Here!
Here is the PHP:
<?php
// index.php
function generate_resized_image(){
$max_dimension = 800; // Max new width or height, can not exceed this value.
$dir = "./images/"; // Directory to save resized image. (Include a trailing slash - /)
// Collect the post variables.
$postvars = array(
"image" => trim($_FILES["image"]["name"]),
"image_tmp" => $_FILES["image"]["tmp_name"],
"image_size" => (int)$_FILES["image"]["size"],
"image_max_width" => (int)$_POST["image_max_width"],
"image_max_height" => (int)$_POST["image_max_height"]
);
// Array of valid extensions.
$valid_exts = array("jpg","jpeg","gif","png");
// Select the extension from the file.
$ext = end(explode(".",strtolower(trim($_FILES["image"]["name"]))));
// Check not larger than 175kb.
if($postvars["image_size"] <= 179200){
// Check is valid extension.
if(in_array($ext,$valid_exts)){
if($ext == "jpg" || $ext == "jpeg"){
$image = imagecreatefromjpeg($postvars["image_tmp"]);
}
else if($ext == "gif"){
$image = imagecreatefromgif($postvars["image_tmp"]);
}
else if($ext == "png"){
$image = imagecreatefrompng($postvars["image_tmp"]);
}
// Grab the width and height of the image.
list($width,$height) = getimagesize($postvars["image_tmp"]);
// If the max width input is greater than max height we base the new image off of that, otherwise we
// use the max height input.
// We get the other dimension by multiplying the quotient of the new width or height divided by
// the old width or height.
if($postvars["image_max_width"] > $postvars["image_max_height"]){
if($postvars["image_max_width"] > $max_dimension){
$newwidth = $max_dimension;
} else {
$newwidth = $postvars["image_max_width"];
}
$newheight = ($newwidth / $width) * $height;
} else {
if($postvars["image_max_height"] > $max_dimension){
$newheight = $max_dimension;
} else {
$newheight = $postvars["image_max_height"];
}
$newwidth = ($newheight / $height) * $width;
}
// Create temporary image file.
$tmp = imagecreatetruecolor($newwidth,$newheight);
// Copy the image to one with the new width and height.
imagecopyresampled($tmp,$image,0,0,0,0,$newwidth,$newheight,$width,$height);
// Create random 4 digit number for filename.
$rand = rand(1000,9999);
$filename = $dir.$rand.$postvars["image"];
// Create image file with 100% quality.
imagejpeg($tmp,$filename,100);
return "<strong>Image Preview:</strong><br/>
<img src=\"".$filename."\" border=\"0\" title=\"Resized Image Preview\" style=\"padding: 4px 0px 4px 0px;background-color:#e0e0e0\" /><br/>
Resized image successfully generated. <a href=\"".$filename."\" target=\"_blank\" name=\"Download your resized image now!\">Click here to download your image.</a>";
imagedestroy($image);
imagedestroy($tmp);
} else {
return "File size too large. Max allowed file size is 175kb.";
}
} else {
return "Invalid file type. You must upload an image file. (jpg, jpeg, gif, png).";
}
}
if(isset($_GET["do"])){
if($_GET["do"] == "upload"){
$upload_and_resize = generate_resized_image();
} else {
$upload_and_resize = "";
}
} else {
$upload_and_resize = "";
}
?>Here is the HTML:
<form action="./index.php?do=upload" method="post" enctype="multipart/form-data">
<table width="100%" align="center" border="0" cellpadding="2" cellspacing="0">
<tr>
<td align="left" width="100">
Max Width:</td>
<td align="left"><input name="image_max_width" style="width: 120px" type="text" maxlength="4" /> px.</td>
</tr>
<tr>
<td align="left">
Max Height:</td>
<td align="left"><input type="text" name="image_max_height" style="width: 120px" maxlength="4" /> px.</td>
</tr>
<tr>
<td align="left">
Image:</td>
<td align="left"><input type="file" name="image" size="40" /></td></tr>
<tr>
<td align="left" colspan="2">
<ol style="margin:0;padding:3px 0px 3px 15px">
<li>Max file size: 175 KB.</li>
<li>Allowed extensions: jpg, jpeg, gif, png.</li>
<li>Max Dimension: <em>800</em>px.</li>
</ol>
</tr>
<tr>
<td align="left" colspan="2">
<input type="submit" name="submit" value="Submit!" style="font: 14pt verdana" />
</td>
</tr>
</table>
</form>This will create a form that looks like this:
Then we just have to call the functions returned value ($upload_and_resize).
<div id="upload">
<?php echo $upload_and_resize; ?>
</div>
6
Popularity: 100% [?]
Filed Under: Featured • Scripts • Tutorials • Web Programming
Thank you for sharing these scripts!
I am a frequent reader of your blog posts. I liked the recent one and other posts on your blog so much that I have subscribed to the blog’s RSS feed in Thunderbird. Even thinking of stealing some ideas and put them to work. Keep all the good work going by posting more informative posts. Thank you. Time well spent on this post.
Thanks so much for sharing all of the awesome information! Looking forward to checking out more.
Hey, I attempted to email you pertaining to this post but aren?t able to reach you. Please e-mail me when get a moment. Thanks.