I'm trying to create a jpeg image summing some png with alpha0 background, but the result is not perfect. the image seems to be composed by stripes that don't match perfectly.
the code is:
<?php
header("Content-type: image/jpeg");
$png1= $_GET['png1'];
$png2= $_GET['png2'];
$png3= $_GET['png3'];
$png4= $_GET['png4'];
$png5= $_GET['png5'];
$im1 = imagecreatefromjpeg("images/background.jpg");
//background image
$im2 = imagecreatefrompng("images/$png1.png");
$im3 = imagecreatefrompng("images/$png2.png");
$im4 = imagecreatefrompng("images/$png3.png");
$im5 = imagecreatefrompng("images/$png4.png");
$im6 = imagecreatefrompng("images/$png5.png");
ImageCopy($im1,$im2,0,0,0,0,608,300);
ImageCopy($im1,$im3,0,0,0,0,608,300);
ImageCopy($im1,$im4,0,0,0,0,608,300);
ImageCopy($im1,$im5,0,0,0,0,608,300);
ImageCopy($im1,$im6,0,0,0,0,608,300);
imagejpeg($im1,'',100); // set to best quality
imagedestroy($im1);
imagedestroy($im2);
imagedestroy($im3);
imagedestroy($im4);
imagedestroy($im5);
imagedestroy($im6);
?>
jpeg and png have same dimensions



