php gd pixelate too sharp - php

Question

i have this script for pixelize my images the script is working but i want more smooth edges:
$imgfile = 'batman.jpg';
$image = ImageCreateFromJPEG($imgfile);
$imagex = imagesx($image);
$imagey = imagesy($image);
$pixelate_amount = 10;
$tmpImage = ImageCreateTrueColor($imagex, $imagey);
imagecopyresized($tmpImage, $image, 0, 0, 0, 0, round($imagex / $pixelate_amount), round($imagey / $pixelate_amount), $imagex, $imagey);
$pixelated = ImageCreateTrueColor($imagex, $imagey);
imagecopyresized($pixelated, $tmpImage, 0, 0, 0, 0, $imagex, $imagey, round($imagex / $pixelate_amount), round($imagey / $pixelate_amount));
header("Content-Type: image/jpeg");
imageJPEG($pixelated, "", 100);
I have:
this produce:
is there anything i miss?

Answer 1

Here's what you need (script I currently use). This script is based from the script at http://www.talkphp.com/19670-post1.html:
function convertToPixel($im, $size) {
$size = (int)$size;
$sizeX = imagesx($im);
$sizeY = imagesy($im);
if($sizeX < 3 && $sizeX < 3) { // or you can choose any size you want
return;
}
for($i = 0;$i < $sizeX; $i += $size) {
for($j = 0;$j < $sizeY; $j += $size) {
$colors = Array('alpha' => 0, 'red' => 0, 'green' => 0, 'blue' => 0, 'total' => 0);
for($k = 0; $k < $size; ++$k) {
for($l = 0; $l < $size; ++$l) {
if($i + $k >= $sizeX || $j + $l >= $sizeY) {
continue;
}
$color = imagecolorat($im, $i + $k, $j + $l);
imagecolordeallocate($im, $color);
$colors['alpha'] += ($color >> 24) & 0xFF;
$colors['red'] += ($color >> 16) & 0xFF;
$colors['green'] += ($color >> 8) & 0xFF;
$colors['blue'] += $color & 0xFF;
++$colors['total'];
}
}
$color = imagecolorallocatealpha($im, $colors['red'] / $colors['total'], $colors['green'] / $colors['total'], $colors['blue'] / $colors['total'], $colors['alpha'] / $colors['total']);
imagefilledrectangle($im, $i, $j, ($i + $size - 1), ($j + $size - 1), $color);
}
}
}
header('Content-type: image/jpg');
$im = imagecreatefromjpeg($imgfile);
convertToPixel($im, 15);
imagejpeg($im, '', 100);
This will produce:
You can also change the value passed in convertToPixel to modify the pixel size.
)

Answer 2

Use imagecopyresampled() instead of imagecopyresized().
http://php.net/manual/en/function.imagecopyresampled.php