I have a lot of JPEG images that I want to convert to PNG images using PHP. The JPEGs are going to be uploaded by clients so I can\'t trust them to make sure they are in the
After a few days of trying different solutions and doing some more research, this is what I found worked for me.
$image = imagecreatefromjpeg( 'image.jpg' );
imagealphablending($image, true);
$transparentcolour = imagecolorallocate($image, 255,255,255);
imagecolortransparent($image, $transparentcolour)
The imagealphablending($image, true); is important.
Using imagesavealpha($f, true); as mentioned in a previous answer definitely doesn't work and seems to actually prevent you from making the background transparent...
To output the transparent image with the correct headers.