Flex does not have any library that supports obtaining the source image height and width on load. If you need to put the image into a container, you will not be able to manipulate the container/image accurately. For example, I was trying to put an image into a container, and set the image to 100% width and 100% height. But this wont work since the container does not have the correct image dimension.
To overcome this, we can make use of PHP's internal function 'getimagesize'. The codes are as follows:
$file = "uploader/upload/" . $row_imageinfo['bitmapurl'];
$info = getimagesize($file);
$width = 0;
$height = 0;
list($width, $height) = $info;
echo("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
echo("<result>");
echo(sprintf("<picurl>%s</picurl>",$row_imageinfo['bitmapurl']));
echo(sprintf("<width>%s</width>", $width));
echo(sprintf("<height>%s</height>", $height));
echo("</result>");
?>