Extracting information out of an image using PHP's internal libraries.

php_image_extract.php

<?php
// loading image: using PHP's GD library to load the image from its file or URL
$img = imagecreatefromjpeg('image.jpg');

// getting image size: using getimagesize() function to get the width and height of the image
list($width, $height) = getimagesize($img);

// extracting image metadata: using exif_read_data() function to extract the image metadata, including camera settings, location, and time
$exif = exif_read_data($img);

// extracting image colors: using imagecolorat() function to extract the color of each pixel in the image
$colors = array();
for ($x = 0; $x < $width; $x++) {
    for ($y = 0; $y < $height; $y++) {
        $color = imagecolorat($img, $x, $y);
        $colors[] = array(
            'r' => ($color >> 16) & 0xFF,
            'g' => ($color >> 8) & 0xFF,
            'b' => $color & 0xFF,
        );
    }
}
?>