$im = imagecreatetruecolor(400, 300);

$c_black = imageColorAllocate($im, 0,0,0);
$c_green = imageColorAllocate($im, 46,204,64);

imageellipse($im, 200, 150, 100, 100, $c_green);

imagewebp($im, '/tmp/image.webp');

• imagecreatetruecolor - creates true color lib:GD image object with specified width & height
• imageColorAllocate - creates color object to later use in image
• imageellipse - creates ellipse with specified coordinates, radius and border color
• imagewebp - saves given gd image in webp format to the specified path
• /tmp/image.webp - path to save image to

group: save_formats