Example

function circle($strokeColor, $fillColor, $backgroundColor, $originX, $originY, $endX, $endY)
{
    //Create a ImagickDraw object to draw into.
    $draw = new \ImagickDraw();

    $strokeColor = new \ImagickPixel($strokeColor);
    $fillColor = new \ImagickPixel($fillColor);

    $draw->setStrokeOpacity(1);
    $draw->setStrokeColor($strokeColor);
    $draw->setFillColor($fillColor);

    $draw->setStrokeWidth(2);
    $draw->setFontSize(72);

    $draw->circle($originX, $originY, $endX, $endY);

    $imagick = new \Imagick();
    $imagick->newImage(500, 500, $backgroundColor);
    $imagick->setImageFormat("png");
    $imagick->drawImage($draw);

    header("Content-Type: image/png");
    echo $imagick->getImageBlob();
}