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PHP Dynamic Image Resizing
<?php
/*
# Dynamic Image Resize .htaccess
RewriteCond %{REQUEST_URI} /resize/(\d+)x(\d+)/(.*)
RewriteRule ^(.*)$ http://www.example.com/resize.php?width=%1&height=%2&file=%3 [L]
*/
// Example Usage: http://www.example.com/resize/300x350/images/example-image.jpg
// Declare Variables
$source_file_name = (file_exists($_GET['file'])) ? $_GET['file'] : 'images/missing-image-75x75.gif';
$source_file_modified = (file_exists($source_file_name)) ? filemtime($source_file_name) : 0;
$source_ext = strtolower(array_pop(explode('.',$source_file_name)));
$mime_types = array('png' => 'image/png','jpe' => 'image/jpeg','jpeg' => 'image/jpeg','jpg' => 'image/jpeg','gif' => 'image/gif');
$mime_type = FALSE;
if (array_key_exists($source_ext, $mime_types)) {
$mime_type = $mime_types[$source_ext];
}
// Set a maximum height and width
// round($_GET['width'], -1); // Round to nearest ten
$width = ( isset($_GET['width']) && $_GET['width'] < 1000 ) ? $_GET['width'] : 100;
$height = ( isset($_GET['height']) && $_GET['width'] < 1000 ) ? $_GET['height'] : 100;
// New dimensions
list($width_orig, $height_orig) = getimagesize($source_file_name);
$ratio_orig = $width_orig/$height_orig;
if ($width/$height > $ratio_orig) {
$width = intval($height*$ratio_orig);
} else {
$height = intval($width/$ratio_orig);
}
// New File Name
$pattern = '/(.*)(\.[a-z]{3,4})$/';
$replacement = '$1_'.$width.'x'.$height.'$2';
$new_file_name = preg_replace($pattern, $replacement, $source_file_name);
$new_file_modified = (file_exists($new_file_name)) ? filemtime($new_file_name) : 0;
// Resample
if( !file_exists($new_file_name) || $source_file_modified > $new_file_modified ){
$image_p = imagecreatetruecolor($width, $height);
switch($mime_type){
case 'image/png':
$image = imagecreatefrompng($source_file_name);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
imagepng($image_p, $new_file_name, 80);
break;
case 'image/gif':
$image = imagecreatefromgif($source_file_name);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
imagegif($image_p, $new_file_name, 80);
break;
case 'image/jpeg':
$image = imagecreatefromjpeg($source_file_name);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
imagejpeg($image_p, $new_file_name, 80);
break;
}
imagedestroy($image_p);
}
// Content type
header('Content-Type: '.$mime_type);
// Output
echo file_get_contents( $new_file_name );
?>
@korgon
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korgon commented Aug 25, 2016

Hi Steve,

I ran into an issue with this PHP resize script when using PNG images.

At line 47: should this be a number between 0-9? Maybe this changed with some new PHP release?
http://php.net/manual/en/function.imagepng.php

Anyways, thanks for this great script!

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