如何使用PHP数组生成动态文本和图像水印

$watermark = array(
    'username' => 'John Smith',
    'timestamp' => date('Y-m-d H:i:s')
);

$textWatermark = sprintf('Username: %s, Generated at: %s', $watermark['username'], $watermark['timestamp']);

$watermark = array(
    'avatar' => '/path/to/avatar.jpg',
    'timestamp' => date('Y-m-d H:i:s')
);

// 创建图像资源
$originalImage = imagecreatefromjpeg($watermark['avatar']);

// 获取原始图像宽度和高度
$originalWidth = imagesx($originalImage);
$originalHeight = imagesy($originalImage);

// 创建包含生成时间的文本水印
$textWatermark = $watermark['timestamp'];
$textWidth = imagefontwidth(5) * strlen($textWatermark);
$textHeight = imagefontheight(5);

// 创建水印图像资源
$watermarkImage = imagecreatetruecolor($originalWidth, $originalHeight);

// 设置透明背景
imagefill($watermarkImage, 0, 0, imagecolorallocatealpha($watermarkImage, 255, 255, 255, 127));
imagesavealpha($watermarkImage, true);

// 复制原始图像到水印图像
imagecopy($watermarkImage, $originalImage, 0, 0, 0, 0, $originalWidth, $originalHeight);

// 在水印图片上添加文本水印
imagettftext($watermarkImage, 12, 0, 10, $originalHeight - 10, imagecolorallocate($watermarkImage, 255, 255, 255), '/path/to/font.ttf', $textWatermark);

// 输出合成后的图像
header('Content-Type: image/jpeg');
imagejpeg($watermarkImage);

// 释放资源
imagedestroy($originalImage);
imagedestroy($watermarkImage);