What are some best practices for creating and manipulating images in PHP to achieve high quality output?

When creating and manipulating images in PHP to achieve high quality output, it is important to use functions provided by the GD library, which is a graphics library for creating dynamic images. Some best practices include using imagecreate() to create a blank image, imagecopyresampled() to resize and manipulate images without losing quality, and imagepng() to output the final image in PNG format.

// Create a blank image with a width and height of 500 pixels
$image = imagecreate(500, 500);

// Resize and manipulate an existing image without losing quality
$original_image = imagecreatefromjpeg('original.jpg');
imagecopyresampled($image, $original_image, 0, 0, 0, 0, 500, 500, imagesx($original_image), imagesy($original_image));

// Output the final image in PNG format
header('Content-Type: image/png');
imagepng($image);
imagedestroy($image);
imagedestroy($original_image);