Start by loading the image, this function will depend entirely on your original image, but for now I assume this is jpeg:
$img = imagecreatefromjpeg('image.jpg');
Then just create a circle on the image:
imagefilledellipse($img, 100, 100, 20, 20, 0x0000FF);
I'm not sure how you want to return it, but to output it to the browser just use the following:
imagejpeg($img);
Jamie hurst
source share