php 生成图片乱码

header('Content-Type: image/png');
$image = imagecreatetruecolor(200, 100);
$bgColor = imagecolorallocate($image, 255, 255, 255);
$textColor = imagecolorallocate($image, 0, 0, 0);
$text = 'Hello, World!';
imagettftext($image, 20, 0, 10, 50, $textColor, 'arial.ttf', $text);
imagepng($image);
imagedestroy($image);

// 使用GD库
$image = imagecreatetruecolor(200, 100);
$bgColor = imagecolorallocate($image, 255, 255, 255);
$textColor = imagecolorallocate($image, 0, 0, 0);
$text = 'Hello, World!';
imagettftext($image, 20, 0, 10, 50, $textColor, 'arial.ttf', $text);
header('Content-Type: image/png');
imagepng($image);
imagedestroy($image);

// 使用Imagick
$image = new Imagick();
$image->newImage(200, 100, 'white');
$image->setImageFormat('png');
$text = new ImagickDraw();
$text->setFontSize(20);
$text->setTextEncoding('UTF-8');
$text->annotateImage($image, 0, 0, 0, 'Hello, World!');
$image->drawImage($text);
header('Content-Type: image/png');
echo $image->getImagesBlob();