php-gdHow to create transparent background

Here we'll draw black filled circle on a transparent background:

<?php

$im = imagecreatetruecolor(400, 300);

imagealphablending($im, false);
$tr = imagecolorallocatealpha($im, 0, 0, 0, 255);
imagefill($im, 0, 0, $tr);
imagesavealpha($im, true);

$c_black = imageColorAllocate($im, 0,0,0);
imagefilledellipse($im, 200, 150, 100, 100, $c_black);

imagePng($im, '/tmp/image.png');ctrl + cgithub

`imagecreatetruecolor` creates true color GD image object with specified width & height	`imagealphablending` we're disabling alpha blending to prevent transparent background being converted to black color
`imagecolorallocatealpha` creates color with transparency (in our case, we just create fully transparent color)	`imagefill(` fills an entire image with a given color (transparent "color" in our case)
`imageColorAllocate` creates color object to later use in image	`imagefilledellipse` creates ellipse with specified coordinates, radius and color
`imagePng` saves image in PNG format to the given path

How to create transparent background, php gd

Usage example

<?php

$im = imagecreatetruecolor(400, 300);

imagealphablending($im, false);
$tr = imagecolorallocatealpha($im, 0, 0, 0, 127);
imagefill($im, 0, 0, $tr);
imagesavealpha($im, true);

$c_black = imageColorAllocate($im, 0,0,0);
imagefilledellipse($im, 200, 150, 100, 100, $c_black);

imagePng($im, '/tmp/image.png');

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php-gdHow to create transparent background

Usage example

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