透明背景PNG的上傳功能

Question

我有上傳PNG圖片與透明背景的問題，結果將是黑色的背景。所有我想要的是在上傳png透明背景後，結果將與原始文件相同。 這裏功能

代碼

upload.php的

function upload_sponsors($nama_file,$folder,$lokasi_file,$lebar,$tinggi){ 
$nama_folder = "../../../$folder/"; 
$ext = end((explode(".", $nama_file))); # extra() to prevent notice 
list($lebar_asli, $tinggi_asli, $source_type) = getimagesize($lokasi_file); 
if ($ext == "gif"){ 
    $gambar_asli = imagecreatefromgif($lokasi_file); 
} else if($ext =="png"){ 
    $gambar_asli = imagecreatefrompng($lokasi_file); 
} else { 
    $gambar_asli = imagecreatefromjpeg($lokasi_file); 
} 

$ukuran_asli = $lebar_asli/$tinggi_asli; 
$ukuran = $lebar/$tinggi; 
if ($ukuran_asli > $ukuran) { 
    $tinggi_sementara = $tinggi; 
    $lebar_sementara = (int) ($tinggi * $ukuran_asli); 
} else { 
    /*jika gambar sama atau lebih tinggi*/ 
    $lebar_sementara = $lebar; 
    $tinggi_sementara = (int) ($lebar/$ukuran_asli); 
} 
$gambar_sementara = imagecreatetruecolor($lebar_sementara, $tinggi_sementara); 
imagecopyresampled($gambar_sementara,$gambar_asli,0, 0,0, 0,$lebar_sementara, $tinggi_sementara,$lebar_asli, $tinggi_asli); 
/*Copy cropped region from temporary image into the desired GD image*/ 
$x_absis = ($lebar_sementara - $lebar)/2; 
$y_absis = ($tinggi_sementara - $tinggi)/2; 
$gambar_akhir = imagecreatetruecolor($lebar, $tinggi); 
imagecopy($gambar_akhir,$gambar_sementara,0, 0,$x_absis, $y_absis,$lebar, $tinggi); 

if ($ext == "gif"){ 
    imagegif($gambar_akhir,$nama_folder.$nama_file); 
} else if($ext =="png"){ 
    imagepng($gambar_akhir,$nama_folder.$nama_file); 
} else { 
    imagejpeg($gambar_akhir,$nama_folder.$nama_file); 
} 

imagedestroy($gambar_akhir); 
} 

那麼這是提交

action.php的

include "../../config/upload.php"; 
$module=$_GET['module']; 
$act=$_GET['act']; 
if ($module=='sponsors' AND $act=='input'){ 
    $ukuran_maksimal  = 30000000; 
    $acak     = rand(0000,9999); 
    $image_info = getimagesize($_FILES["fupload"]["tmp_name"]); 
    $lebar = $image_info[0]; // width of image 
    $tinggi = $image_info[1]; // height of image 
    //$lebar    = 800; 
    //$tinggi     = 534; 

    //$fold     = $_POST['folder']; 
    $id_kategori   = $_POST['id_kategori_blog']; 
    $folder     = "images/"; 
    $lokasi_file   = $_FILES['fupload']['tmp_name']; 
    $tipe_file    = $_FILES['fupload']['type']; 
    $nama_file    = $_FILES['fupload']['name']; 
    $ukuran_file   = $_FILES['fupload']['size']; 
    $nama_file    = str_replace(' ', '_', $nama_file); 
    $nama_file    = $acak.$nama_file; 

    upload_sponsors($nama_file,$folder,$lokasi_file,$lebar,$tinggi); 

       mysql_query("INSERT INTO sponsors(judul,link,isi,gambar) 
             VALUES('$_POST[judul]','$_POST[link]','$_POST[isi]','$nama_file')"); 
       echo "<script>window.alert('Upload image succes'); 
       window.location=('../../main.php?module=sponsors')</script>"; 

} 

Answer 1

您需要填寫的畫布與透明形式上傳後的動作顏色，在複製重新採樣之前，像這樣：

imagefill($gambar_sementara, 0, 0, 0x7fff0000); 

0x7fff0000是完全透明顏色的十六進制代碼字符串。您還可以使用imagecolorallocatealpha()來構建透明顏色。

還需要使用imagesavealpha()啓用alpha通道。

在您的代碼：

$gambar_sementara = imagecreatetruecolor($lebar_sementara, $tinggi_sementara); 
imagesavealpha($gambar_sementara, true); 
imagefill($gambar_sementara, 0, 0, 0x7fff0000); 
imagecopyresampled($gambar_sementara,$gambar_asli,0, 0,0, 0,$lebar_sementara, $tinggi_sementara,$lebar_asli, $tinggi_asli); 

進一步回落：

$gambar_akhir = imagecreatetruecolor($lebar, $tinggi); 
imagesavealpha($gambar_akhir, true); 
imagefill($gambar_akhir, 0, 0, 0x7fff0000); 
imagecopy($gambar_akhir,$gambar_sementara,0, 0,$x_absis, $y_absis,$lebar, $tinggi); 

參見：

http://php.net/manual/en/function.imagefill.php http://php.net/manual/en/function.imagesavealpha.php http://php.net/manual/en/function.imagecolorallocatealpha.php