Here is the complete implementation to display image using imagepng() in image tag of HTML
<?php
$im = imagecreatefrompng("path of image);
if ( $im ) {
ob_start();
imagepng($im);
$imgData=ob_get_clean();
imagedestroy($im);
echo '<img src="data:image/png;base64,'.base64_encode($imgData).'" />';
}
?>