On my previous post I was shown an example how to upload file with php and html. It was based on php simple image upload functionality. Today I am going to show you little bit advance of image uploading. Suppose if you run a website and want to allow users to upload image files than you need to think little bit about server's space and bandwidth. For this purpose you need to do some optimization with image files. Image resize while uploading is one of them. All major website do it in the same way. If a user uploads a 5mb image file they resize it in different sizes and store on there server. It helps them to seed up there website and reduce there budget. Now take a look, how we can do it ourself.
Live Demo Download Source
PHP and HTML(index.php)
This file holds the basic of file uploading html markup and simple php upload handler.
Resize Function(function.php):
Resize function is based on PHP GD library.
Live Demo Download Source
PHP and HTML(index.php)
This file holds the basic of file uploading html markup and simple php upload handler.
<?php
include( 'function.php');
// settings
$max_file_size = 1024*200; // 200kb
$valid_exts = array('jpeg', 'jpg', 'png', 'gif');
// thumbnail sizes
$sizes = array(100 => 100, 150 => 150, 250 => 250);
if ($_SERVER['REQUEST_METHOD'] == 'POST' AND isset($_FILES['image'])) {
if( $_FILES['image']['size'] < $max_file_size ){
// get file extension
$ext = strtolower(pathinfo($_FILES['image']['name'], PATHINFO_EXTENSION));
if (in_array($ext, $valid_exts)) {
/* resize image */
foreach ($sizes as $w => $h) {
$files[] = resize($w, $h);
}
} else {
$msg = 'Unsupported file';
}
} else{
$msg = 'Please upload image smaller than 200KB';
}
}
?>
<html>
<head>
<title>Image resize while uploadin</title>
<head>
<body>
<!-- file uploading form -->
<form action="" method="post" enctype="multipart/form-data">
<label>
<span>Choose image</span>
<input type="file" name="image" accept="image/*" />
</label>
<input type="submit" value="Upload" />
</form>
</body>
</html>
Resize Function(function.php):
Resize function is based on PHP GD library.
/**
* Image resize
* @param int $width
* @param int $height
*/
function resize($width, $height){
/* Get original image x y*/
list($w, $h) = getimagesize($_FILES['image']['tmp_name']);
/* calculate new image size with ratio */
$ratio = max($width/$w, $height/$h);
$h = ceil($height / $ratio);
$x = ($w - $width / $ratio) / 2;
$w = ceil($width / $ratio);
/* new file name */
$path = 'uploads/'.$width.'x'.$height.'_'.$_FILES['image']['name'];
/* read binary data from image file */
$imgString = file_get_contents($_FILES['image']['tmp_name']);
/* create image from string */
$image = imagecreatefromstring($imgString);
$tmp = imagecreatetruecolor($width, $height);
imagecopyresampled($tmp, $image,
0, 0,
$x, 0,
$width, $height,
$w, $h);
/* Save image */
switch ($_FILES['image']['type']) {
case 'image/jpeg':
imagejpeg($tmp, $path, 100);
break;
case 'image/png':
imagepng($tmp, $path, 0);
break;
case 'image/gif':
imagegif($tmp, $path);
break;
default:
exit;
break;
}
return $path;
/* cleanup memory */
imagedestroy($image);
imagedestroy($tmp);
}
Hi make sure image uploading is blocked when the file input is empty
ReplyDeleteYeah! We can do it by applying isset($_FILES['image'] or is_uploaded_file($_FILES['image']['tmp_name'] condition
DeleteIts working..
ReplyDeleteThanks!
Is it possible to resize multiple images at same time using this way?
ReplyDeleteGood question! Of course it is possible!
DeleteYou need to add multiple attributable on file input.
For detail see here
how to resize images in shape of ladder ...
ReplyDeleteHey I used class for this. How to resize multiple image using the same code. What part of the PHP code we need to change. Because when i tried to take images in loop, i got error of class can not be re-declared. Please help me off in this. Thanks in advance
ReplyDeletenice code
ReplyDeleteThere is a problem with resize when uploading .PNG image, it shows black image.
ReplyDeleteIts all about transparency!
DeletePlease see this resource: http://stackoverflow.com/questions/32243/can-png-image-transparency-be-preserved-when-using-phps-gdlib-imagecopyresample
Hi, can you tell me how to insert the name of the resized file into a DB? I am trying to insert it but am unsure which variable to use.
ReplyDeleteThanks!
You can store original file name using $_FILES['image']['name'] and rather you can call your file like this way uploads/100x100_yourfilename.jpg
DeleteIs there a quick modification that would allow this to respect the aspect ratio of the original file? Currently all images are cropped according to the height and width parameters? Is there a way to set the width to auto?
ReplyDeleteWould like to keep the aspect ratio too, as NativePaul mentioned! Examples?
ReplyDeleteI'm not a PHP expert but once you retun a value form a function what's after is not executed.
ReplyDeleteSo this code is never reached:
/* cleanup memory */
imagedestroy($image);
imagedestroy($tmp);
That is correct. Once a return is reached, the function is exited. The return should ALWAYS (ok, there are few exceptions...) be the last line of a function
DeleteNice! Thankyou for the code..
ReplyDelete