Get Alpha from PNG created with imagepng()

Frank,

Here is your solution with code

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>Test</title>

    </head>
    <body>

        <a href="index.php" class="navbar-brand">
            <?php
            $x = 1;
            $y = 1;
            $gd = imagecreatetruecolor($x, $y);
            imageAlphaBlending($gd, false);
            imageSaveAlpha($gd, true);
            imagesetpixel($gd, 0, 0, imagecolorallocatealpha($gd, 200, 200, 200, 1));
            imagepng($gd, 'img/logo.png" ');
            imagedestroy($gd);

            $im = imagecreatefrompng('img/logo.png');
            $rgb = imagecolorat($im, 0, 0);
            $colors = imagecolorsforindex($im, $rgb);
            $red = (int) $colors["red"];
            $blue = (int) $colors["blue"];
            $green = (int) $colors["green"];
            echo $alpha = (int) $colors["alpha"]; // return only 0
            ?>
        </a>

    </body>
</html>

You should call imageAlphaBlending and imageSaveAlpha before calling imagesetpixel :

imageAlphaBlending($gd, false);
imageSaveAlpha($gd, true);
imagesetpixel($gd, 0,0, imagecolorallocatealpha($gd, 200,200,200,1));

Tags:

Php

Png

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