";
//Catat waktu mulainya
echo "";
for ($u = 1; $u <= 1; $u++) {
$time_start = microtime(true);
// pembentukan citra digital
$gambar_digital = imagecreatefromjpeg($gambar_awal);
// mencari dimensi gambar
$data_gambar = getimagesize($gambar_awal);
//Menyiapkan kanvas untuk citra baru
$akhir = imagecreatetruecolor($data_gambar[0],$data_gambar[1]);
// Proses semua piksel
$ubah_pixel = 0;
$total_ambil_pixel = 0;
for($x=1;$x<$data_gambar[0]-1;$x++){
for($y=1;$y<$data_gambar[1]-1;$y++){
//nilai pixel aslinya
$sebelum = gray(imagecolorat($gambar_digital, $x, $y));
// Hitung semua nilai abu-abu di sekitar piksel yang discan
$proses1 = microtime(true);
$a = gray(imagecolorat($gambar_digital,$x,$y-1));
$b = gray(imagecolorat($gambar_digital, $x, $y+1));
$c = gray(imagecolorat($gambar_digital,$x-1,$y));
$d = gray(imagecolorat($gambar_digital, $x+1, $y));
$e = gray(imagecolorat($gambar_digital,$x-1, $y-1));
$f = gray(imagecolorat($gambar_digital, $x+1, $y-1));
$g = gray(imagecolorat($gambar_digital,$x-1, $y+1));
$h = gray(imagecolorat($gambar_digital, $x+1, $y+1));
$proses2 = microtime(true);
$lama_ambil_pixel = $proses2-$proses1;
$total_ambil_pixel = $total_ambil_pixel + $lama_ambil_pixel;
//menghitung median
$abu_abu = mencari_median($a,$b,$c,$d,$e,$f,$g,$h);
$selisih = abs($sebelum - $abu_abu);
if ($selisih >= $given_tol) {
//tanam nilai abu-abu tersebut pada kanvas yang sudah kita siapkan
$abu_new=imagecolorallocate($gambar_digital,$abu_abu,$abu_abu,$abu_abu);
imagesetpixel($gambar_digital,$x,$y,$abu_new);
$ubah_pixel++;
}
}
}
//Catat waktu selesai
$time_end = microtime(true);
//Hitung lama waktu eksekusinya
$time = ($time_end - $time_start) - $total_ambil_pixel; ;
echo "| $ubah_pixel | $time |
";
}
echo "
";
// Tampilkan Citra lama dan citra baru
$citra_baru = "coba_enhance_lena".$given_tol."-".$test_ke.".jpg";
imagejpeg($gambar_digital, $citra_baru, 100);
echo "
";
echo "
";
}
function gray($pixel){
$pixel = sprintf('%06x',$pixel);
$red = hexdec(substr($pixel,0,2))*0.30;
$green = hexdec(substr($pixel,2,2))*0.59;
$blue = hexdec(substr($pixel,4))*0.11;
return $red+$green+$blue;
}
function mencari_median($a,$b,$c,$d,$e,$f,$g,$h) {
$nilai_tetangga = array($a,$b,$c,$d,$e,$f,$g,$h);
sort($nilai_tetangga);
$bawah = $nilai_tetangga[3];
$atas = $nilai_tetangga[4];
$abu_abu = floor(($bawah+$atas)/2);
return $abu_abu;
}
?>