Imagick not working and showing null image - php

Question

I am using shared hosting and extensions is installed too, the following code not working and just showing blank image in output I have tried many of code/function of Imagick all of codes showing the following image.
Please help me out.
<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
// Create objects
$image = new Imagick('image.png');
$watermark = new Imagick();
$mask = new Imagick();
$draw = new ImagickDraw();
// Define dimensions
$width = $image->getImageWidth();
$height = $image->getImageHeight();
// Create some palettes
$watermark->newImage($width, $height, new ImagickPixel('grey30'));
$mask->newImage($width, $height, new ImagickPixel('black'));
// Watermark text
$text = 'Copyright';
// Set font properties
$draw->setFont('arial.ttf');
$draw->setFontSize(20);
$draw->setFillColor('grey70');
// Position text at the bottom right of the image
$draw->setGravity(Imagick::GRAVITY_SOUTHEAST);
// Draw text on the watermark palette
$watermark->annotateImage($draw, 10, 12, 0, $text);
// Draw text on the mask palette
$draw->setFillColor('white');
$mask->annotateImage($draw, 11, 13, 0, $text);
$mask->annotateImage($draw, 10, 12, 0, $text);
$draw->setFillColor('black');
$mask->annotateImage($draw, 9, 11, 0, $text);
// This is needed for the mask to work
$mask->setImageMatte(false);
// Apply mask to watermark
$watermark->compositeImage($mask, Imagick::COMPOSITE_COPYOPACITY, 0, 0);
// Overlay watermark on image
$image->compositeImage($watermark, Imagick::COMPOSITE_DISSOLVE, 0, 0);
// Set output image format
$image->setImageFormat('png');
// Output the new image
header('Content-type: image/png');
echo $image;