25

I'm trying to create a transparent png image and layer various other pngs and jpgs to create a final png with transparency. I'm having trouble creating my initial empty transparent png. It currently has a white background.

Can anyone point me in the right direction. This is my code so far...

$image = imagecreatetruecolor(485, 500);
imagealphablending($image, false);
imagesavealpha($image, true);
$col=imagecolorallocatealpha($image,255,255,255,127);
imagefill($image, 0, 0, $col);
//imagefilledrectangle($image,0,0,485, 500,$col);


/* add door glass */
$img_doorGlass = imagecreatefrompng("glass/$doorStyle/$doorGlass.png");     
imagecopyresampled($image, $img_doorGlass, 106, 15, 0, 0, 185, 450, 185, 450);              


/* add door */
$img_doorStyle = imagecreatefrompng("door/$doorStyle/$doorStyle"."_"."$doorColor.png");     
imagecopyresampled($image, $img_doorStyle, 106, 15, 0, 0, 185, 450, 185, 450);


$fn = md5(microtime()."door_builder").".png";

if(imagepng($image, "user_doors/$fn", 1)){
  echo "user_doors/$fn";
}       
imagedestroy($image);
michael
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  • does the change in blending mode help? Don't have the images to test myself, but it would seem that the png images should blend. Otherwise the image is created just as per php docs and user-contributed notes, so can't see the problem there, sorry – ashein May 24 '11 at 11:51

3 Answers3

31

Set imagealphablending($image,true); on each new layer.

Try this:

<?php
$image = imagecreatetruecolor(485, 500);
imagealphablending($image, false);
$col=imagecolorallocatealpha($image,255,255,255,127);
imagefilledrectangle($image,0,0,485, 500,$col);
imagealphablending($image,true);

/* add door glass */
$img_doorGlass = imagecreatefrompng("glass/$doorStyle/$doorGlass.png");
imagecopyresampled($image, $img_doorGlass, 106, 15, 0, 0, 185, 450, 185, 450);
imagealphablending($image,true);

/* add door */
$img_doorStyle = imagecreatefrompng("door/$doorStyle/$doorStyle"."_"."$doorColor.png");
imagecopyresampled($image, $img_doorStyle, 106, 15, 0, 0, 185, 450, 185, 450);
imagealphablending($image,true);

$fn = md5(microtime()."door_builder").".png";

imagealphablending($image,false);
imagesavealpha($image,true);
if(imagepng($image, "user_doors/$fn", 1)){
    echo "user_doors/$fn";
}
imagedestroy($image);

?>
Lawrence Cherone
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  • not 100% sure why, but this works. thanks for your help Lawrence – michael May 24 '11 at 12:51
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    np, it works because `imagealphablending($image,true);` is set to true on every new png added to the layer then lastly `imagesavealpha($image,true);` before save, you had it at the top. sometimes it will get reset – Lawrence Cherone May 24 '11 at 12:57
3

This code worked for me:

$img=imagecreatetruecolor(180,20);
imagealphablending($img,false);

$col=imagecolorallocatealpha($img,255,255,255,127);
imagefilledrectangle($img,0,0,180,20,$col);
imagealphablending($img,true);

$font=$_SERVER["DOCUMENT_ROOT"].'/fonts/Arial.ttf';
$color = imagecolorallocate($img, 140, 173, 209);
imagettftext($img,11,0,5,14,$color,$font,'Text goes here'); 

header('Content-Type: image/png');
imagealphablending($img,false);
imagesavealpha($img,true);
imagepng($img);
Gaurav Dave
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ishubin
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0

Try to replace
$col=imagecolorallocatealpha($image,255,255,255,127);
with
$col=imagecolorallocate($image,255,255,255);

and try to uncomment imagefilledrectangle line.
I can test this code - give me the pictures :)

OZ_
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