从iPhone上传图像会删除exif数据

我建立了一个允许图片上传的网站，一旦图片上传，就会显示有关照片的一些具体信息。从电脑上传图片没问题，但当我试图从智能手机上传图片时，问题就出现了。上传成功了，但是似乎从计算机上传时显示的大部分数据现在丢失了。

以下代码段实际检索并显示数据:

$location = $_FILES["pic"]["tmp_name"];
$data = exif_read_data($location);
var_dump($data);

var_dump($data)实际上在计算机和智能手机中转储不同的数据。

显然它在Android智能手机上工作得很好，只有当我试图从iPhone上传图像时才会出现这个问题。

例如，var_dump from computer upload:

array(49) { 
    ["FileName"]=> string(10) "php2D4.tmp" 
    ["FileDateTime"]=> int(1367318152) 
    ["FileSize"]=> int(30357) 
    ["FileType"]=> int(2) 
    ["MimeType"]=> string(10) "image/jpeg" 
    ["SectionsFound"]=> string(24) "ANY_TAG, IFD0, EXIF, GPS" 
    ["COMPUTED"]=> array(6) { 
        ["html"]=> string(24) "width="320" height="240""  
        ["Height"]=> int(240)  
        ["Width"]=> int(320)  
        ["IsColor"]=> int(1)  
        ["ByteOrderMotorola"]=> int(1)  
        ["ApertureFNumber"]=> string(5) "f/2.8"  
    }  
    ["Make"]=> string(5) "Apple"  
    ["Model"]=> string(8) "iPhone 4"  
    ["Orientation"]=> int(3)  
    ["XResolution"]=> string(4) "72/1"  
    ["YResolution"]=> string(4) "72/1"  
    ["ResolutionUnit"]=> int(2)  
    ["Software"]=> string(5) "6.1.3"  
    ["DateTime"]=> string(19) "2013:04:26 23:57:43"  
    ["YCbCrPositioning"]=> int(1)  
    ["Exif_IFD_Pointer"]=> int(204)  
    ["GPS_IFD_Pointer"]=> int(594)  
    ["ExposureTime"]=> string(4) "1/15"  
    ["FNumber"]=> string(4) "14/5"  
    ["ExposureProgram"]=> int(2)  
    ["ISOSpeedRatings"]=> int(1000)  
    ["ExifVersion"]=> string(4) "0221"  
    ["DateTimeOriginal"]=> string(19) "2013:04:26 23:57:43"  
    ["DateTimeDigitized"]=> string(19) "2013:04:26 23:57:43"  
    ["ComponentsConfiguration"]=> string(4) ""  
    ["ShutterSpeedValue"]=> string(9) "4889/1250"  
    ["ApertureValue"]=> string(9) "4281/1441"  
    ["BrightnessValue"]=> string(10) "-3581/1451"  
    ["MeteringMode"]=> int(5)  
    ["Flash"]=> int(24)  
    ["FocalLength"]=> string(5) "77/20"  
    ["SubjectLocation"]=> array(4) {  
        [0]=> int(1295) 
        [1]=> int(967) 
        [2]=> int(699) 
        [3]=> int(696) 
    } 
    ["FlashPixVersion"]=> string(4) "0100" 
    ["ColorSpace"]=> int(1) 
    ["ExifImageWidth"]=> int(2592) 
    ["ExifImageLength"]=> int(1936) 
    ["SensingMethod"]=> int(2) 
    ["ExposureMode"]=> int(0) 
    ["WhiteBalance"]=> int(0) 
    ["FocalLengthIn35mmFilm"]=> int(35) 
    ["SceneCaptureType"]=> int(0) 
    ["GPSLatitudeRef"]=> string(1) "N" 
    ["GPSLatitude"]=> array(3) { 
        [0]=> string(4) "31/1" 
        [1]=> string(8) "5854/100" 
        [2]=> string(3) "0/1" 
    } 
    ["GPSLongitudeRef"]=> string(1) "E" 
    ["GPSLongitude"]=> array(3) { 
        [0]=> string(4) "34/1" 
        [1]=> string(8) "4684/100" 
        [2]=> string(3) "0/1" 
    } 
    ["GPSTimeStamp"]=> array(3) { 
        [0]=> string(4) "20/1" 
        [1]=> string(4) "57/1" 
        [2]=> string(8) "4272/100" 
    } 
    ["GPSImgDirectionRef"]=> string(1) "T" 
    ["GPSImgDirection"]=> string(9) "48089/465" 
}

var_dump from smartphone upload:

array(12) { 
    ["FileName"]=> string(9) "phpSzwfPw" 
    ["FileDateTime"]=> int(1367318054) 
    ["FileSize"]=> int(1778041) 
    ["FileType"]=> int(2) 
    ["MimeType"]=> string(10) "image/jpeg" 
    ["SectionsFound"]=> string(19) "ANY_TAG, IFD0, EXIF" 
    ["COMPUTED"]=> array(5) { 
        ["html"]=> string(26) "width="2592" height="1936"" 
        ["Height"]=> int(1936) 
        ["Width"]=> int(2592) 
        ["IsColor"]=> int(1) 
        ["ByteOrderMotorola"]=> int(1) 
    } 
    ["Orientation"]=> int(3) 
    ["Exif_IFD_Pointer"]=> int(38) 
    ["ColorSpace"]=> int(1) 
    ["ExifImageWidth"]=> int(2592) 
    ["ExifImageLength"]=> int(1936) 
}

这是计算机 var_dump($_FILES):

    array(1) 
{ ["pic"]=> array(5) 
{ ["name"]=> string(18) leaf2.JPG" 
["type"]=> string(10) "image/jpeg" 
["tmp_name"]=> string(14) "/tmp/phpzeDUs9"
 ["error"]=> int(0)
 ["size"]=> int(46439) } }

这是iPhone结果var_dump($_FILES):

    array(1) { ["pic"]=> array(5) 
{ ["name"]=> string(9) "image.jpg" 
["type"]=> string(10) "image/jpeg" 
["tmp_name"]=> string(14) "/tmp/phplPUZky" 
["error"]=> int(0) ["size"]=> int(1455577) } } 

编辑:这是上传表单的HTML代码:

     <form action="results.php" id="upload-image" method="post" enctype="multipart/form-data">
         <div class="fileupload fileupload-new" data-provides="fileupload">
          <div class="fileupload-preview thumbnail" style="width: 200px; height: 150px;"></div>
          <div>
            <span class="btn btn-file"><span class="fileupload-new">Select image</span><span class="fileupload-exists">Change</span><input type="file" name="pic" id="pic" accept="image/*"/></span>
            <a href="#" class="btn fileupload-exists" data-dismiss="fileupload">Remove</a>
            <button type="submit" class="btn">Upload</button>
            </br>
            <span class="upload-error"></span>
          </div>
     </form>

是什么原因引起的?