PHP Image quality issue on rotating and merging - php

Question

When i merge two images as one background and the other as target image. I m using pngs. When I rotate the target image and then merge, yes everything is fine except that the edges of rotated image becomes zigzag i means not smooth. How to make the edges smooth using php GD???
The code I am using:
<?php
// Create image instances
$dest = imagecreatefrompng('bg.png');
$src = imagecreatefrompng('text.png');
$width = imagesx($src);
$height = imagesy($src);
imageantialias($src, true);
$color = imagecolorallocatealpha($src, 0, 0, 0, 127);
$rotated = imagerotate($src, 40, $color);
imagesavealpha($rotated, true);
// $trans_colour = imagecolorallocatealpha($rotated, 0, 0, 0, 127);
// imagefill($rotated, 0, 0, $trans_colour);
imagepng($rotated, 'shahid.png');
$new_img = imagecreatefrompng('shahid.png?');
$width = imagesx($new_img);
$height = imagesy($new_img);
// imagecopymerge($dest, $new_img, 50, 50, 0, 0, $width+60, $height+60, 100);
imagecopymerge_alpha($dest, $new_img, 0, 20, 0, 0, $width, $height, 100);
// Output and free from memory
header('Content-Type: image/png');
imagepng($dest);
imagedestroy($dest);
imagedestroy($src);
function imagecopymerge_alpha($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h, $pct)
{
if (!isset($pct)) {
return false;
}
$pct/= 100;
// Get image width and height
$w = imagesx($src_im);
$h = imagesy($src_im);
// Turn alpha blending off
imagealphablending($src_im, false);
// Find the most opaque pixel in the image (the one with the smallest alpha value)
$minalpha = 127;
for ($x = 0; $x < $w; $x++)
for ($y = 0; $y < $h; $y++) {
$alpha = (imagecolorat($src_im, $x, $y) >> 24) & 0xFF;
if ($alpha < $minalpha) {
$minalpha = $alpha;
}
}
// loop through image pixels and modify alpha for each
for ($x = 0; $x < $w; $x++) {
for ($y = 0; $y < $h; $y++) {
// get current alpha value (represents the TANSPARENCY!)
$colorxy = imagecolorat($src_im, $x, $y);
$alpha = ($colorxy >> 24) & 0xFF;
// calculate new alpha
if ($minalpha !== 127) {
$alpha = 127 + 127 * $pct * ($alpha - 127) / (127 - $minalpha);
}
else {
$alpha+= 127 * $pct;
}
// get the color index with new alpha
$alphacolorxy = imagecolorallocatealpha($src_im, ($colorxy >> 16) & 0xFF, ($colorxy >> 8) & 0xFF, $colorxy & 0xFF, $alpha);
// set pixel with the new color + opacity
if (!imagesetpixel($src_im, $x, $y, $alphacolorxy)) {
return false;
}
}
}
// The image copy
imagecopy($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h);
}
?>

Answer 1

I had this in an old project and worked for me. Anyway, I don't remember if my pngs had really alpha transparency or "gif" transparency...
$image = imagecreatefrompng($href);
$newImage = imagecreatefrompng($href2);
imagealphablending($image, true);
imagealphablending($newImage, true);
$newImage = imagerotate($newImage, $r, -1);
$blue = imagecolorallocate($newImage, 0, 0,255);
imagecolortransparent($newImage, $blue);
imagecopy($image,$newImage,$x,$y,0,0,imagesx($newImage) , imagesy($newImage));
From the manual, in that case, imagealphablending should be replaced by imagesavealpha