我正在使用一个脚本，让用户上传图像。脚本调整大小并将图像转换为JPEG。

我遇到的问题是上传透明度的PNG时，生成的JPEG图像是透明度为黑色的图像。

如何编辑下面的脚本来替换黑色的白色？它已经为GIF而做，但不是PNG的。

// RESIZE IMAGE AND PUT IN USER DIRECTORY

switch($this->file_ext)

{

case "gif":

$file = imagecreatetruecolor($width, $height);

$new = imagecreatefromgif($this->file_tempname);

$kek=imagecolorallocate($file, 255, 255, 255);

imagefill($file,0,0,$kek);

imagecopyresampled($file, $new, 0, 0, 0, 0, $width, $height, $this->file_width, $this->file_height);

imagejpeg($file, $photo_dest, 100);

ImageDestroy($new);

ImageDestroy($file);

break;

case "bmp":

$file = imagecreatetruecolor($width, $height);

$new = $this->imagecreatefrombmp($this->file_tempname);

for($i=0; $i<256; $i++) { imagecolorallocate($file, $i, $i, $i); }

imagecopyresampled($file, $new, 0, 0, 0, 0, $width, $height, $this->file_width, $this->file_height);

imagejpeg($file, $photo_dest, 100);

ImageDestroy($new);

ImageDestroy($file);

break;

case "jpeg":

case "jpg":

$file = imagecreatetruecolor($width, $height);

$new = imagecreatefromjpeg($this->file_tempname);

for($i=0; $i<256; $i++) { imagecolorallocate($file, $i, $i, $i); }

imagecopyresampled($file, $new, 0, 0, 0, 0, $width, $height, $this->file_width, $this->file_height);

imagejpeg($file, $photo_dest, 100);

ImageDestroy($new);

ImageDestroy($file);

break;

case "png":

$file = imagecreatetruecolor($width, $height);

$new = imagecreatefrompng($this->file_tempname);

for($i=0; $i<256; $i++) { imagecolorallocate($file, $i, $i, $i); }

imagecopyresampled($file, $new, 0, 0, 0, 0, $width, $height, $this->file_width, $this->file_height);

imagejpeg($file, $photo_dest, 100);

ImageDestroy($new);

ImageDestroy($file);

break;

}

chmod($photo_dest, 0777);

return true;

}

我尝试编辑案例“png”：部分匹配案例“gif”：代码，但生成的JPEG是完全白色的。

更新：

我自己修好了

谢谢大家，贡献！

我换了

case "png":

$file = imagecreatetruecolor($width, $height);

$new = imagecreatefrompng($this->file_tempname);

for($i=0; $i<256; $i++) { imagecolorallocate($file, $i, $i, $i); }

imagecopyresampled($file, $new, 0, 0, 0, 0, $width, $height, $this->file_width, $this->file_height);

imagejpeg($file, $photo_dest, 100);

ImageDestroy($new);

ImageDestroy($file);

break;

有：

case "png":

$file = imagecreatetruecolor($width, $height);

$new = imagecreatefrompng($this->file_tempname);

$kek=imagecolorallocate($file, 255, 255, 255);

imagefill($file,0,0,$kek);

imagecopyresampled($file, $new, 0, 0, 0, 0, $width, $height, $this->file_width, $this->file_height);

imagejpeg($file, $photo_dest, 100);

ImageDestroy($new);

ImageDestroy($file);

break;