Resize images in PHP without using third-party libraries?
Solution 1:
Finally, I've discovered a way that fit my needs. The following snippet will resize an image to the specified width, automatically calculating the height in order to keep the proportion.
$image = $_FILES["image"]["tmp_name"];
$resizedDestination = $uploadDirectory.md5($randomNumber.$filename)."_RESIZED.jpg";
copy($_FILES, $resizedDestination);
$imageSize = getImageSize($image);
$imageWidth = $imageSize[0];
$imageHeight = $imageSize[1];
$DESIRED_WIDTH = 100;
$proportionalHeight = round(($DESIRED_WIDTH * $imageHeight) / $imageWidth);
$originalImage = imageCreateFromJPEG($image);
$resizedImage = imageCreateTrueColor($DESIRED_WIDTH, $proportionalHeight);
imageCopyResampled($images_fin, $originalImage, 0, 0, 0, 0, $DESIRED_WIDTH+1, $proportionalHeight+1, $imageWidth, $imageHeight);
imageJPEG($resizedImage, $resizedDestination);
imageDestroy($originalImage);
imageDestroy($resizedImage);
To anyone else seeking a complete example, create two files:
<!-- send.html -->
<html>
<head>
<title>Simple File Upload</title>
</head>
<body>
<center>
<div style="margin-top:50px; padding:20px; border:1px solid #CECECE;">
Select an image.
<br/>
<br/>
<form action="receive.php" enctype="multipart/form-data" method="post">
<input type="file" name="image" size="40">
<input type="submit" value="Send">
</form>
</div>
</center>
</body>
<?php
// receive.php
$randomNumber = rand(0, 99999);
$uploadDirectory = "images/";
$filename = basename($_FILES['file_contents']['name']);
$destination = $uploadDirectory.md5($randomNumber.$filename).".jpg";
echo "File path:".$filePath."<br/>";
if (is_uploaded_file($_FILES["image"]["tmp_name"]) == true) {
echo "File successfully received through HTTP POST.<br/>";
// Validate the file size, accept files under 5 MB (~5e+6 bytes).
if ($_FILES['image']['size'] <= 5000000) {
echo "File size: ".$_FILES["image"]["size"]." bytes.<br/>";
// Resize and save the image.
$image = $_FILES["image"]["tmp_name"];
$resizedDestination = $uploadDirectory.md5($randomNumber.$filename)."_RESIZED.jpg";
copy($_FILES, $resizedDestination);
$imageSize = getImageSize($image);
$imageWidth = $imageSize[0];
$imageHeight = $imageSize[1];
$DESIRED_WIDTH = 100;
$proportionalHeight = round(($DESIRED_WIDTH * $imageHeight) / $imageWidth);
$originalImage = imageCreateFromJPEG($image);
$resizedImage = imageCreateTrueColor($DESIRED_WIDTH, $proportionalHeight);
imageCopyResampled($images_fin, $originalImage, 0, 0, 0, 0, $DESIRED_WIDTH+1, $proportionalHeight+1, $imageWidth, $imageHeight);
imageJPEG($resizedImage, $resizedDestination);
imageDestroy($originalImage);
imageDestroy($resizedImage);
// Save the original image.
if (move_uploaded_file($_FILES['image']['tmp_name'], $destination) == true) {
echo "Copied the original file to the specified destination.<br/>";
}
}
}
?>
Solution 2:
I made a small function to resize images, the function is below:
function resize_image($path, $width, $height, $update = false) {
$size = getimagesize($path);// [width, height, type index]
$types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');
if ( array_key_exists($size['2'], $types) ) {
$load = 'imagecreatefrom' . $types[$size['2']];
$save = 'image' . $types[$size['2']];
$image = $load($path);
$resized = imagecreatetruecolor($width, $height);
$transparent = imagecolorallocatealpha($resized, 0, 0, 0, 127);
imagesavealpha($resized, true);
imagefill($resized, 0, 0, $transparent);
imagecopyresampled($resized, $image, 0, 0, 0, 0, $width, $height, $size['0'], $size['1']);
imagedestroy($image);
return $save($resized, $update ? $path : null);
}
}
And here's how you use it:
if ( resize_image('dir/image.png', 50, 50, true) ) {// resize image.png to 50x50
echo 'image resized!';
}
Solution 3:
there is 1 very simple image re-size function for all image types that keeps transparency and is very easy to use
check out :
https://github.com/Nimrod007/PHP_image_resize
hope this helps
Solution 4:
ImageMagick is the fastest and probably the best way to resize images in PHP. Check out different examples here. This sample shows how to resize and image on upload.
Solution 5:
Thanks to Mateus Nunes! i edited his work a bit to get transparent pngs working:
$source = $_FILES["..."]["tmp_name"];
$destination = 'abc/def/ghi.png';
$maxsize = 45;
$size = getimagesize($source);
$width_orig = $size[0];
$height_orig = $size[1];
unset($size);
$height = $maxsize+1;
$width = $maxsize;
while($height > $maxsize){
$height = round($width*$height_orig/$width_orig);
$width = ($height > $maxsize)?--$width:$width;
}
unset($width_orig,$height_orig,$maxsize);
$images_orig = imagecreatefromstring( file_get_contents($source) );
$photoX = imagesx($images_orig);
$photoY = imagesy($images_orig);
$images_fin = imagecreatetruecolor($width,$height);
imagesavealpha($images_fin,true);
$trans_colour = imagecolorallocatealpha($images_fin,0,0,0,127);
imagefill($images_fin,0,0,$trans_colour);
unset($trans_colour);
ImageCopyResampled($images_fin,$images_orig,0,0,0,0,$width+1,$height+1,$photoX,$photoY);
unset($photoX,$photoY,$width,$height);
imagepng($images_fin,$destination);
unset($destination);
ImageDestroy($images_orig);
ImageDestroy($images_fin);