如何在PHP中的圖像中添加水印

• Create or load the source image using imagecreatefromjpeg() , imagecreatefrompng() , or similar.
• Allocate a color for the text using imagecolorallocate() .
• Use imagestring() or imagettftext() to add text to the image.
• Output or save the final image with imagejpeg() or imagepng() .

// Load the image
$im = imagecreatefromjpeg('photo.jpg');
<p>// Set the watermark text
$text = '© MySite.com';</p> <p>// Set font size and font path (TTF font recommended)
$font = 'arial.ttf';
$font_size = 20;</p> <p>// Allocate color (R, G, B)
$color = imagecolorallocate($im, 255, 255, 255); // White text</p> <p>// Get image dimensions
$width = imagesx($im);
$height = imagesy($im);</p> <p>// Calculate position (bottom-right)
$text_box = imagettfbbox($font_size, 0, $font, $text);
$text_width = $text_box[4] - $text_box[0];
$x = $width - $text_width - 10;
$y = $height - 10;</p> <p>// Add the text
imagettftext($im, $font_size, 0, $x, $y, $color, $font, $text);</p> <p>// Save the image
imagejpeg($im, 'watermarked.jpg', 90);</p> <p>// Free memory
imagedestroy($im);</p>

• Load both the main image and the watermark image.
• Use imagecopy() or imagecopymerge() to place the watermark.
• Adjust position and opacity as needed.
• Save the result.

// Load the main image
$main = imagecreatefromjpeg('photo.jpg');
<p>// Load the watermark (PNG with transparency)
$watermark = imagecreatefrompng('logo.png');</p> <p>// Get dimensions
$main_w = imagesx($main);
$main_h = imagesy($main);
$watermark_w = imagesx($watermark);
$watermark_h = imagesy($watermark);</p> <p>// Set position (eg, bottom-right)
$dest_x = $main_w - $watermark_w - 10;
$dest_y = $main_h - $watermark_h - 10;</p> <p>// Merge watermark (100% opacity; use imagecopymerge for transparency)
imagecopy($main, $watermark, $dest_x, $dest_y, 0, 0, $watermark_w, $watermark_h);</p> <p>// Save the image
imagejpeg($main, 'watermarked.jpg', 90);</p> <p>// Free memory
imagedestroy($main);
imagedestroy($watermark);</p>