CODEWITHSUNDEEP
phpimageimage-resizing
Mateus
Mateus

Reputation: 2668

Resize images in PHP without using third-party libraries?

In one of my applications, I'm using the code snippet below to copy uploaded images to a directory. It works fine but copying large images (> 2MB) takes more time than ideal and I really don't need images this big, so, I'm looking for a way to resize the images. How to achieve this using PHP?

<?php

$uploadDirectory = 'images/0001/';
$randomNumber = rand(0, 99999); 
$filename = basename($_FILES['userfile']['name']);
$filePath = $uploadDirectory.md5($randomNumber.$filename);

// Check if the file was sent through HTTP POST.

if (is_uploaded_file($_FILES['userfile']['tmp_name']) == true) {

    // Validate the file size, accept files under 5 MB (~5e+6 bytes).

    if ($_FILES['userfile']['size'] <= 5000000) {

        // Move the file to the path specified.

        if (move_uploaded_file($_FILES['userfile']['tmp_name'], $filePath) == true) {

            // ...

        }

    }

}

?>

Upvotes: 14

Views: 81199

Answers (6)

TURTLE
TURTLE

Reputation: 3847

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!';
}

Upvotes: 10

Mateus
Mateus

Reputation: 2668

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/>";

        }

    }

}

?>

Upvotes: 35

cottton
cottton

Reputation: 1607

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);

Upvotes: 1

Nimrod007
Nimrod007

Reputation: 9913

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

Upvotes: 8

FellowCoder
FellowCoder

Reputation: 51

You could also use an x*y/width method for resizing and then calling imagecopyresampled() like is shown at http://www.virtualsecrets.com/upload-resize-image-php-mysql.html That page also puts images (after resizing) into mySQL via the PDO.

Upvotes: 0

Chibueze Opata
Chibueze Opata

Reputation: 10044

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.

Upvotes: 3

Related Questions