Imagecreatefrompng() Makes a Black Background Instead of Transparent

imagecreatefrompng() Makes a black background instead of transparent?

After imagecreatetruecolor():

<?php

// ... Before imagecreatetruecolor()

$dimg = imagecreatetruecolor($width_new, $height_new); // png ?: gif

// start changes
switch ($stype) {

    case 'gif':
    case 'png':
        // integer representation of the color black (rgb: 0,0,0)
        $background = imagecolorallocate($dimg , 0, 0, 0);
        // removing the black from the placeholder
        imagecolortransparent($dimg, $background);

        // turning off alpha blending (to ensure alpha channel information
        // is preserved, rather than removed (blending with the rest of the
        // image in the form of black))
        imagealphablending($dimg, false);

        // turning on alpha channel information saving (to ensure the full range
        // of transparency is preserved)
        imagesavealpha($dimg, true);
        break;

    default:
        break;
}
// end changes

$wm = $w/$nw;
$hm = $h/$nh;

// ...

imagecreatefrompng() transparent part of png is black

Well that was easy XD Converting comment to answer:

Your mistake was in defining the background colour. You should use this:

$background = imagecolorallocatealpha($src,0,0,0,127);

However, it is probably a good idea to be safe, and avoid using a "transparent" colour that already exists on your image. The "traditional" transparent colour from old sprite-based games is magenta, since it is very unlikely that you'll have straight magenta on your image!

$background = imagecolorallocatealpha($src,255,0,255,127);

PHP GD - transparent PNG black background

It should be something along the lines of:

switch ($source_type)
{
 case IMAGETYPE_PNG:

    $background = imagecolorallocate($source, 0, 0, 0);
    // remove the black 
    imagecolortransparent($source, $background);

    // turn off alpha blending
    imagealphablending($source, false);


    imagesavealpha($source, true);

    break;
}

There is a similar question here

Black background instead of transparent on PNG images when processing them

This $background = imagecolorallocate($newimg, 0, 0, 0); is for black background

use $background = imagecolorallocatealpha($newimg, 255, 255, 255); instead

PNG with transparent background = thumbnail with black backgroud

Using:

$tci = imagecreate($w, $h);

Instead:

$tci = imagecreatetruecolor($w, $h);

My issue is now solved :)

PHP GD - Transparent areas goes black

You should call these two functions before saving the png image, imagealphablending() and imagesavealpha():

imagealphablending( $image, false );
imagesavealpha( $image, true );

Can PNG image transparency be preserved when using PHP's GDlib imagecopyresampled?

imagealphablending( $targetImage, false );
imagesavealpha( $targetImage, true );

did it for me. Thanks ceejayoz.

note, the target image needs the alpha settings, not the source image.

Edit:
full replacement code. See also answers below and their comments. This is not guaranteed to be be perfect in any way, but did achieve my needs at the time.

$uploadTempFile = $myField[ 'tmp_name' ]
list( $uploadWidth, $uploadHeight, $uploadType ) 
  = getimagesize( $uploadTempFile );

$srcImage = imagecreatefrompng( $uploadTempFile ); 

$targetImage = imagecreatetruecolor( 128, 128 );   
imagealphablending( $targetImage, false );
imagesavealpha( $targetImage, true );

imagecopyresampled( $targetImage, $srcImage, 
                    0, 0, 
                    0, 0, 
                    128, 128, 
                    $uploadWidth, $uploadHeight );

imagepng(  $targetImage, 'out.png', 9 );

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