Exploring a Faster Image Dimension Retrieval in PHP

In the realm of PHP programming, it can become cumbersome to retrieve image dimensions using the default getimagesize function when dealing with a large volume of remote images. To address this bottleneck, let's delve into an alternative approach that promises lightning-fast performance.

By leveraging the file_get_contents function, we can read only a limited number of bytes from an image. This data can then be meticulously examined to determine the image's dimensions.

To embark on this approach, let's consider the following code snippet:

function ranger($url){
    $headers = array(
    "Range: bytes=0-32768"
    );

    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    $data = curl_exec($curl);
    curl_close($curl);
    return $data;
}

$start = microtime(true);

$url = "http://news.softpedia.com/images/news2/Debian-Turns-15-2.jpeg";

$raw = ranger($url);
$im = imagecreatefromstring($raw);

$width = imagesx($im);
$height = imagesy($im);

$stop = round(microtime(true) - $start, 5);

echo $width." x ".$height." ({$stop}s)";

This function utilizes the ranger function to retrieve a small portion of the image data. Subsequently, imagecreatefromstring is employed to generate an image resource from the retrieved data. Lastly, imagesx and imagesy furnish us with the width and height of the image, respectively.

When put to the test with an image URL, this approach demonstrated impressive speed, as seen below:

640 x 480 (0.20859s)

In this instance, extracting the image's dimensions took only 0.20859 seconds, highlighting the efficiency of this method.

By harnessing the power of reading a limited amount of data from remote images, we have devised a remarkably fast and efficient way to obtain image dimensions in PHP. This technique empowers you to tackle the challenge of processing numerous images with ease and speed.