好的，所以我意识到有成千上万的问题与这类事情有关，但似乎没有任何答案可以满足我的需求。所以这是我的问题。
我有一个房地产CRM系统，几家公司用它来存储他们的房产详细信息和图像，然后我将这些信息和图像提供给他们宣传所述房产的各种不同的房产门户网站。现在他们显然要求那些照片被加水印，我的系统允许他们以两种方式这样做，方法是在中心有一个透明的，或者在右下角有一个不透明的小的。根据此设置的不同，这会反映在生成并发送到各个站点的XML Feed中的图像URL中。他们当然可以自由地更改徽标等，而不会出现图像硬拷贝等问题。
现在当使用右下角水印时没有问题，因为当一些门户网站抓住所有图像并且我正在谈论成千上万的时候，PHP处理的情况要小得多，而且每天都会增加数量+加入它自然超载VPS服务器和inmotionhosting切断了我。这是我正在使用的第三方脚本，它可以完美地使用太多资源。有任何改进的想法吗？我知道人们提到了缓存，但每个图像都不同，可能只需要一次，那么它会受益吗？所有的帮助都表示赞赏，因为这是我在扩展系统时头痛的问题。提前谢谢！
<?php
class watermark{
# given two images, return a blended watermarked image
function create_watermark( $main_img_obj, $watermark_img_obj, $alpha_level = 100 ) {
$alpha_level /= 100; # convert 0-100 (%) alpha to decimal
# calculate our images dimensions
$main_img_obj_w = imagesx( $main_img_obj );
$main_img_obj_h = imagesy( $main_img_obj );
$watermark_img_obj_w = imagesx( $watermark_img_obj );
$watermark_img_obj_h = imagesy( $watermark_img_obj );
# determine center position coordinates
$main_img_obj_min_x = floor( ( $main_img_obj_w / 2 ) - ( $watermark_img_obj_w / 2 ) );
$main_img_obj_max_x = ceil( ( $main_img_obj_w / 2 ) + ( $watermark_img_obj_w / 2 ) );
$main_img_obj_min_y = floor( ( $main_img_obj_h / 2 ) - ( $watermark_img_obj_h / 2 ) );
$main_img_obj_max_y = ceil( ( $main_img_obj_h / 2 ) + ( $watermark_img_obj_h / 2 ) );
# create new image to hold merged changes
$return_img = imagecreatetruecolor( $main_img_obj_w, $main_img_obj_h );
# walk through main image
for( $y = 0; $y < $main_img_obj_h; $y++ ) {
for( $x = 0; $x < $main_img_obj_w; $x++ ) {
$return_color = NULL;
# determine the correct pixel location within our watermark
$watermark_x = $x - $main_img_obj_min_x;
$watermark_y = $y - $main_img_obj_min_y;
# fetch color information for both of our images
$main_rgb = imagecolorsforindex( $main_img_obj, imagecolorat( $main_img_obj, $x, $y ) );
# if our watermark has a non-transparent value at this pixel intersection
# and we're still within the bounds of the watermark image
if ( $watermark_x >= 0 && $watermark_x < $watermark_img_obj_w &&
$watermark_y >= 0 && $watermark_y < $watermark_img_obj_h ) {
$watermark_rbg = imagecolorsforindex( $watermark_img_obj, imagecolorat( $watermark_img_obj, $watermark_x, $watermark_y ) );
# using image alpha, and user specified alpha, calculate average
$watermark_alpha = round( ( ( 127 - $watermark_rbg['alpha'] ) / 127 ), 2 );
$watermark_alpha = $watermark_alpha * $alpha_level;
# calculate the color 'average' between the two - taking into account the specified alpha level
$avg_red = $this->_get_ave_color( $main_rgb['red'], $watermark_rbg['red'], $watermark_alpha );
$avg_green = $this->_get_ave_color( $main_rgb['green'], $watermark_rbg['green'], $watermark_alpha );
$avg_blue = $this->_get_ave_color( $main_rgb['blue'], $watermark_rbg['blue'], $watermark_alpha );
# calculate a color index value using the average RGB values we've determined
$return_color = $this->_get_image_color( $return_img, $avg_red, $avg_green, $avg_blue );
# if we're not dealing with an average color here, then let's just copy over the main color
} else {
$return_color = imagecolorat( $main_img_obj, $x, $y );
} # END if watermark
# draw the appropriate color onto the return image
imagesetpixel( $return_img, $x, $y, $return_color );
} # END for each X pixel
} # END for each Y pixel
# return the resulting, watermarked image for display
return $return_img;
} # END create_watermark()
# average two colors given an alpha
function _get_ave_color( $color_a, $color_b, $alpha_level ) {
return round( ( ( $color_a * ( 1 - $alpha_level ) ) + ( $color_b * $alpha_level ) ) );
} # END _get_ave_color()
# return closest pallette-color match for RGB values
function _get_image_color($im, $r, $g, $b) {
$c=imagecolorexact($im, $r, $g, $b);
if ($c!=-1) return $c;
$c=imagecolorallocate($im, $r, $g, $b);
if ($c!=-1) return $c;
return imagecolorclosest($im, $r, $g, $b);
} # EBD _get_image_color()
} # END watermark API
?>
<?php
# include our watermerking class
include 'api.watermark.php';
$watermark = new watermark();
# create image objects using our user-specified images
# NOTE: we're just going to assume we're dealing with a JPG and a PNG here - for example purposes
$imgtype = exif_imagetype ( $_GET['main'] );
if($imgtype === 3){
$main_img_obj = imagecreatefrompng( $_GET['main']);
}else if($imgtype === 2){
$main_img_obj = imagecreatefromjpeg( $_GET['main']);
}else if($imgtype === 1){
$main_img_obj = imagecreatefromgif( $_GET['main']);
}else if($imgtype === 6){
$main_img_obj = imagecreatefrombmp( $_GET['main']);
}
$watermark_img_obj = imagecreatefrompng( $_GET['watermark']);
# create our watermarked image - set 66% alpha transparency for our watermark
$return_img_obj = $watermark->create_watermark( $main_img_obj, $watermark_img_obj, 30 );
# display our watermarked image - first telling the browser that it's a JPEG,
# and that it should be displayed inline
if(($imgtype === 3)or($imgtype === 2)){
header( 'Content-Type: image/png','Content-Type: image/jpeg');
}else if(($imgtype === 1)or($imgtype === 6)){
header( 'Content-Type: image/gif','Content-Type: image/bmp');
}
header( 'Content-Disposition: inline; filename=' . $_GET['src'] );
imagejpeg( $return_img_obj, '', 50 );
?>
答案 0 :(得分：0)
我认为你并没有缓存每次都可能重复使用的水印图像。
除此之外，我不认为PHP是用于此类工作的工具。我会寻找一个可以在PHP中使用的外部库来执行此操作。 PHP很好，只是不适合这种工作。您可以在这里（以及其他地方）查看PHP和其他语言之间的大量内存/ CPU密集型任务的相对性能;
http://benchmarksgame.alioth.debian.org/u32/compare.php?lang=gcc&lang2=php
答案 1 :(得分：0)
您应该使用GD imagecopymerge而不是迭代像素。并缓存结果（如果使用基于.htaccess的重定向来奖励积分，以避免为缓存图像调用PHP）。