Utilisez cette classe, avant de mettre la marque d'eau faites juste la copie de l'image originale.
<?php
class Watermark{
# given two images, return a blended watermarked image
# 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
?>
ce qui est de savoir comment utiliser
$watermark = new Watermark();
$actual_image = imagecreatefromjpeg("images/$image_file");
$watermark_image = imagecreatefrompng("images/water_mark.png");
//create water marked image with 66% transparency
$return_img_obj = $watermark->create_watermark($actual_image, $watermark_image, 66);
//now save the updated image
imagejpeg($return_img_obj,"images/$image_file1");
//clear the memory
imagedestroy($actual_image);
imagedestroy($watermark_image);
imagedestroy($return_img_obj);
Veuillez ajouter plus de contexte. Qu'est-ce que vous avez besoin de cela? Pourquoi l'image originale ne doit-elle pas être affectée? S'il vous plaît clarifier –
Vous devez faire une copie de votre image source et l'utiliser pour la manipulation – JohnP