php 图片怎么转换成二进制流

//获取临时文件名
$strTmpName = $_FILES['file']['tmp_name'];

//转成二进制流
$strData = base64EncodeImage(strTmpName );

//输出
<img src=&#39;$strData&#39;>

function base64EncodeImage($strTmpName)
{
    $base64Image = '';
    $imageInfo   = getimagesize($strTmpName);
    $imageData   = fread(fopen($strTmpName , 'r'), filesize($strTmpName));
    $base64Image = 'data:' . $imageInfo['mime'] . ';base64,' . chunk_split(base64_encode($imageData));
    return $base64Image;
}