使用php为图像添加"水印"

Question

我有一个用户可以上传图片的网站......

我需要在图片上传后添加我的徽标(水印).

我怎么能这样做？

并且重要的是水印位于可见的角落,例如我已经看到在飞行中生成水印的网站,并且在主图像的背景为"相同颜色"的任何地方放置标记,因此如果你知道我的意思,水印会突出.

有人有一个很好的教程或文章吗？或者知道php中的任何函数我需要找到水印的位置？

Answer 1

PHP手册中的一个很好的例子:

// Load the stamp and the photo to apply the watermark to
$stamp = imagecreatefrompng('stamp.png');
$im = imagecreatefromjpeg('photo.jpeg');

// Set the margins for the stamp and get the height/width of the stamp image
$marge_right = 10;
$marge_bottom = 10;
$sx = imagesx($stamp);
$sy = imagesy($stamp);

// Copy the stamp image onto our photo using the margin offsets and the photo 
// width to calculate positioning of the stamp. 
imagecopy($im, $stamp, imagesx($im) - $sx - $marge_right, imagesy($im) - $sy - $marge_bottom, 0, 0, imagesx($stamp), imagesy($stamp));

// Output and free memory
header('Content-type: image/png');
imagepng($im);
imagedestroy($im);

Answer 2

使用此功能
水印图像的类型必须是"png"

 function watermark_image($target, $wtrmrk_file, $newcopy) {
    $watermark = imagecreatefrompng($wtrmrk_file);
    imagealphablending($watermark, false);
    imagesavealpha($watermark, true);
    $img = imagecreatefromjpeg($target);
    $img_w = imagesx($img);
    $img_h = imagesy($img);
    $wtrmrk_w = imagesx($watermark);
    $wtrmrk_h = imagesy($watermark);
    $dst_x = ($img_w / 2) - ($wtrmrk_w / 2); // For centering the watermark on any image
    $dst_y = ($img_h / 2) - ($wtrmrk_h / 2); // For centering the watermark on any image
    imagecopy($img, $watermark, $dst_x, $dst_y, 0, 0, $wtrmrk_w, $wtrmrk_h);
    imagejpeg($img, $newcopy, 100);
    imagedestroy($img);
    imagedestroy($watermark);
}

watermark_image('image_name.jpg','watermark.png', 'new_image_name.jpg');

Answer 3

水印图像的好例子,位于中心

<?php
// Load the stamp and the photo to apply the watermark to
$stamp = imagecreatefrompng('stampimg.png');
$im = imagecreatefrompng('mainimage.png');

// Set the margins for the stamp and get the height/width of the stamp image
$marge_right = 10;
$marge_bottom = 10;
$sx = imagesx($stamp);
$sy = imagesy($stamp);

$imgx = imagesx($im);
$imgy = imagesy($im);
$centerX=round($imgx/2);
$centerY=round($imgy/2);

// Copy the stamp image onto our photo using the margin offsets and the photo 
// width to calculate positioning of the stamp. 
imagecopy($im, $stamp, $centerX, $centerY, 0, 0, imagesx($stamp), imagesy($stamp));

// Output and free memory
header('Content-type: image/png');
imagepng($im);
imagedestroy($im);
?>