php GD problems with transparency.

[Sim]

I am trying to overlap these images to create a new character. I am having problems with my transparency stuff...

Code:

Code: [Select]

<?php
session_start();


//body is never empty
$im = imagecreatefrompng("images/chars/body" . str_replace(' ', '',$_SESSION['body'] . ".png"));

//set pixel color for transparent
$green = imagecolorallocate($im, 51, 153, 0);

// Make the background transparent
imagecolortransparent($im, $green);

//bottom
if(!empty($_SESSION['bot']))
{
$newImage = imagecreatefrompng("images/chars/bot" . str_replace(' ', '',$_SESSION['bot']) . ".png");
//set pixel color for transparent
$green = imagecolorallocate($newImage, 51, 153, 0);

// Make the background transparent
imagecolortransparent($newImage, $green);

imagecopymerge($newImage, $im, 0, 0, 0, 0, 48, 64, 0);
}

//top
if(!empty($_SESSION['top']))
{
if(!empty($_SESSION['bot']))
{
$newImage = imagecreatefrompng("images/chars/top" . str_replace(' ', '',$_SESSION['top']) . ".png");
//set pixel color for transparent
$green = imagecolorallocate($newImage, 51, 153, 0);

// Make the background transparent
imagecolortransparent($newImage, $green);

// Copy and merge
imagecopymerge($newImage, $im, 0, 0, 0, 0, 48, 64, 0);

// Content type
header('Content-type: image/png');
imagepng($newImage);
}
else
{
$newImager = imagecreatefrompng("images/chars/bot" . str_replace(' ', '',$_SESSION['bot']) . ".png");
//set pixel color for transparent
$green = imagecolorallocate($newImager, 51, 153, 0);

// Make the background transparent
imagecolortransparent($newImager, $green);

imagecopymerge($newImager, $im, 0, 0, 0, 0, 48, 64, 0);

// Content type
header('Content-type: image/png');
imagepng($newImager);
}
}



?>


[Nox]

http://cz.php.net/manual/en/function.imagesavealpha.php is your friend

[CygnusX]

I need more information.  I'm guessing you're trying to place the head/armor on the generic body?  What results are you getting when you try to make the switch?  Is it throwing an error?  Or, are you trying to obtain some sort of 'transparency' as stated in your post?  

[Sim]

Still having problems...
Doesn't keep my colors from all 3 images. It like lightens them.

http://phpengines.info/tactical/indexcreate.php

Code: [Select]

<?php
session_start();

$rgb = "32, 156, 0";

//body is never empty
$im = imagecreatefrompng("images/chars/body" . str_replace(' ', '',$_SESSION['body'] . ".png"));


//set pixel color for transparent
$green = imagecolorallocate($im, 32, 156, 0);

// Make the background transparent
imagecolortransparent($im, $green);

// Turn off alpha blending and set alpha flag
imagealphablending($im, false);
imagesavealpha($im, true);
//bottom
if(!empty($_SESSION['bot']))
{
$newImage = imagecreatefrompng("images/chars/bot" . str_replace(' ', '',$_SESSION['bot']) . ".png");
//set pixel color for transparent
$green = imagecolorallocate($newImage, 32, 156, 0);

// Make the background transparent
imagecolortransparent($newImage, $green);

// Turn off alpha blending and set alpha flag
imagealphablending($newImage, false);
imagesavealpha($newImage, true);
imagecopymerge($im, $newImage, 0, 0, 0, 0, 48, 64, 75);

//set pixel color for transparent
$green = imagecolorallocate($im, 32, 156, 0);

// Make the background transparent
imagecolortransparent($im, $green);
}


//top
if(!empty($_SESSION['top']))
{
$newImager = imagecreatefrompng("images/chars/top" . str_replace(' ', '',$_SESSION['top']) . ".png");
//set pixel color for transparent
$green = imagecolorallocate($newImager, 32, 156, 75);

// Make the background transparent
imagecolortransparent($newImager, $green);
// Turn off alpha blending and set alpha flag
imagealphablending($newImager, false);
imagesavealpha($newImager, true);
imagecopymerge($im, $newImager, 0, 0, 0, 0, 48, 64, 75);
}

// Content type
header('Content-type: image/png');
imagepng($im);

?>

[CygnusX]

2 things:

1) you only need to declare the value of $green once.  Doing it twice is not good practice.

2)  I suggest reading through all the comments on php's site for the functions you're using.  There seem to be many problems with transparencies, alpha bleeding, etc.  I can't 'see' what your image looks like, so its hard to diagnose the problem. 

[Sim]

Since my last post, i was trying to make it work so you may not have seen what it originally looked like. I have read  through all the function's i been using several times. I just can't figure it out. below is what the image looks like.

[Chris]

Try converting all images to 24bit. GD has problems if you mix palette based images and true colour images.

Generally, GD has flaws, it does not give you errors when you do something "wrong" and just do not do it instead. The worst things is that these "wrong" things are not intuitive (like palette images behaviour).

[codestryke]

Code: [Select]

<?php
  $imgOutput = imagecreatetruecolor(48, 64);
  imagefill($imgOutput, 0, 0, 0);

  $imgBody = imagecreatefrompng("body.png");
  imagecolortransparent($imgBody, imagecolorat($imgBody, 0, 0));

  $imgBeard = imagecreatefrompng("beard.png");
  imagecolortransparent($imgBeard, imagecolorat($imgBeard, 0, 0));

  $imgArmour = imagecreatefrompng("armour.png");
  imagecolortransparent($imgArmour, imagecolorat($imgArmour, 0, 0));
  
  imagecopymerge($imgOutput, $imgBody, 0, 0, 0, 0, 48, 64, 100);
  imagecopymerge($imgOutput, $imgBeard, 0, 0, 0, 0, 48, 64, 100);
  imagecopymerge($imgOutput, $imgArmour, 0, 0, 0, 0, 48, 64, 100);

  imagepng($imgOutput, './imagecolortransparent.png');
  imagedestroy($imgOutput);
  exit;
?>

This will output the result to a black background, if you would like that changed to a different color or image change the first two lines that define the output. I did not define a var for the transparency color as they may be slightly different across the images.

[Mufasa]

I know it's not a solution to the GD problem, but we've moved to Image Magick for all our processing needs. SO. Much. Better. If you CAN do it, I'd highly recommend it.

[Sim]

I know it's not a solution to the GD problem, but we've moved to Image Magick for all our processing needs. SO. Much. Better. If you CAN do it, I'd highly recommend it.

I'm having problems with Image Magick and png's too. Not the same problems, but when trying to use png's for animated gif's.

[Sim]

works like a charm!!! Thanks coderstryke.

Code: [Select]

<?php
  $imgOutput = imagecreatetruecolor(48, 64);
  imagefill($imgOutput, 0, 0, 0);

  $imgBody = imagecreatefrompng("body.png");
  imagecolortransparent($imgBody, imagecolorat($imgBody, 0, 0));

  $imgBeard = imagecreatefrompng("beard.png");
  imagecolortransparent($imgBeard, imagecolorat($imgBeard, 0, 0));

  $imgArmour = imagecreatefrompng("armour.png");
  imagecolortransparent($imgArmour, imagecolorat($imgArmour, 0, 0));
  
  imagecopymerge($imgOutput, $imgBody, 0, 0, 0, 0, 48, 64, 100);
  imagecopymerge($imgOutput, $imgBeard, 0, 0, 0, 0, 48, 64, 100);
  imagecopymerge($imgOutput, $imgArmour, 0, 0, 0, 0, 48, 64, 100);

  imagepng($imgOutput, './imagecolortransparent.png');
  imagedestroy($imgOutput);
  exit;
?>

This will output the result to a black background, if you would like that changed to a different color or image change the first two lines that define the output. I did not define a var for the transparency color as they may be slightly different across the images.