Are there any specific PHP functions or libraries that facilitate progressive image loading?

Progressive image loading involves loading images gradually to improve user experience by displaying a low-quality image first and then progressively rendering higher quality versions. One way to achieve this in PHP is by using the `imagecreatefromjpeg()` function to create an image resource from a JPEG file and then outputting the image progressively using the `imagejpeg()` function with a lower quality parameter initially and increasing it over time. 

<?php
// Path to the original image file
$original_image = 'original.jpg';

// Create an image resource from the original image
$source = imagecreatefromjpeg($original_image);

// Output the image progressively with decreasing quality
for ($quality = 100; $quality >= 10; $quality -= 10) {
    ob_start();
    imagejpeg($source, null, $quality);
    $output = ob_get_clean();
    
    // Output the image data for progressive loading
    echo $output;
    
    // Flush the output buffer
    ob_flush();
    
    // Delay for a short period to simulate progressive loading
    usleep(50000); // 50 milliseconds
}

// Free up memory by destroying the image resource
imagedestroy($source);
?>

Keywords

PHP image loading progressive loading libraries functions

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