【摘要】Exif就是在JPEG格式头部插入了数码照片的信息，包括拍摄时的光圈、快门、白平衡、ISO、焦距、日期时间等各种和拍摄条件以及相机品牌、型号、色彩编码、拍摄时录制的声音以及全球定位系统(GPS)、缩略图等。简单地说，Exif=JPEG+拍摄参数。因此，你可以利用任何可以查看JPEG文件的看图软件浏览Exif格式的照片，但并不是所有的图形程序都能处理Exif信息。
确保php在编译的时候已经开启了exif，如：–enable-exif
查看php是否已经支持exif模块，可以通过phpinfo()查看，也可以通过命令行方式：
php -i | grep -i exif
exif
EXIF Support => enabled
EXIF Version => 1.4 $Id$
Supported EXIF Version => 0220
exif.decode_jis_intel => JIS => JIS
exif.decode_jis_motorola => JIS => JIS
exif.decode_unicode_intel => UCS-2LE => UCS-2LE
exif.decode_unicode_motorola => UCS-2BE => UCS-2BE
exif.encode_jis => no value => no value
exif.encode_unicode => ISO-8859-15 => ISO-8859-15
1
2
3
4
5
6
7
8
9
10
11
php-i|grep-iexif
exif
EXIFSupport=>enabled
EXIFVersion=>1.4$Id$
SupportedEXIFVersion=>0220
exif.decode_jis_intel=>JIS=>JIS
exif.decode_jis_motorola=>JIS=>JIS
exif.decode_unicode_intel=>UCS-2LE=>UCS-2LE
exif.decode_unicode_motorola=>UCS-2BE=>UCS-2BE
exif.encode_jis=>novalue=>novalue
exif.encode_unicode=>ISO-8859-15=>ISO-8859-15
下面是一个php读取exif的函数
php_exif_test.php
header("Content-Type: text/html; charset=utf-8");
function getExif($img){
#$exif = exif_read_data($img, 'IFD0');
$exif = exif_read_data($img);
return array (
'文件名' => $exif['FileName'],
'文件类型' => $exif['FileType'],
'器材品牌' => $exif['Make'],
'器材' => $exif['Model'],
'快门' => $exif['ExposureTime'],
'光圈' => $exif['FNumber'],
'焦距' => $exif['FocalLength'],
'感光度' => $exif['ISOSpeedRatings'],
'文件格式' => $exif['MimeType'],
'时间戳' => $exif['DateTime'],
'图片说明' => $exif['ImageDescription'],
'方向1' => $exif['Orientation'],
'方向2' => $Orientation[$exif['Orientation']],
'水平分辨率' => $exif['XResolution'].$exif['ResolutionUnit'],
'垂直分辨率' => $exif['YResolution'].$exif['ResolutionUnit'],
'作者' => $exif['Artist'],
# 'YCbCr位置控制' => $YCbCrPositioning[$exif['YCbCrPositioning']],
# 'YCbCr位置控制' => $exif['YCbCrPositioning'],
'版权' => $exif['Copyright'],
'Exif版本' => $exif['ExifVersion'],
'拍摄分辨率高' => $exif['COMPUTED']['Height'],
'拍摄分辨率宽' => $exif['COMPUTED']['Width'],
'拍摄时间' => $exif['DateTimeOriginal'],
);
}
$exif = getExif('pic1.jpg');
echo '
';
print_r($exif);
echo '
';
?>
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
php_exif_test.php
header("Content-Type: text/html; charset=utf-8");
functiongetExif($img){
#$exif = exif_read_data($img, 'IFD0');
$exif=exif_read_data($img);
returnarray(
'文件名'=>$exif['FileName'],
'文件类型'=>$exif['FileType'],
'器材品牌'=>$exif['Make'],
'器材'=>$exif['Model'],
'快门'=>$exif['ExposureTime'],
'光圈'=>$exif['FNumber'],
'焦距'=>$exif['FocalLength'],
'感光度'=>$exif['ISOSpeedRatings'],
'文件格式'=>$exif['MimeType'],
'时间戳'=>$exif['DateTime'],
'图片说明'=>$exif['ImageDescription'],
'方向1'=>$exif['Orientation'],
'方向2'=>$Orientation[$exif['Orientation']],
'水平分辨率'=>$exif['XResolution'].$exif['ResolutionUnit'],
'垂直分辨率'=>$exif['YResolution'].$exif['ResolutionUnit'],
'作者'=>$exif['Artist'],
#'YCbCr位置控制' => $YCbCrPositioning[$exif['YCbCrPositioning']],
#'YCbCr位置控制' => $exif['YCbCrPositioning'],
'版权'=>$exif['Copyright'],
'Exif版本'=>$exif['ExifVersion'],
'拍摄分辨率高'=>$exif['COMPUTED']['Height'],
'拍摄分辨率宽'=>$exif['COMPUTED']['Width'],
'拍摄时间'=>$exif['DateTimeOriginal'],
);
}
$exif=getExif('pic1.jpg');
echo'
';
print_r($exif);
echo'
';
?>
执行结果如下：
图片一：
(
[文件名] => pic1.jpg
[文件类型] => 2
[器材品牌] => Canon
[器材] => Canon EOS 5D Mark II
[快门] => 1/25
[光圈] => 14/10
[焦距] => 35/1
[感光度] => 2000
[文件格式] => image/jpeg
[时间戳] => -07-24T13:43:47+08:00
[图片说明] =>
[方向1] =>
[方向2] =>
[水平分辨率] => 350/12
[垂直分辨率] => 350/12
[作者] => Photographer: Fisher
[版权] => Copyright:clycsz3
[Exif版本] => 0220
[拍摄分辨率高] => 500
[拍摄分辨率宽] => 750
[拍摄时间] => :07:04 01:12:22
)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
(
[文件名] => pic1.jpg
[文件类型] => 2
[器材品牌] => Canon
[器材] => Canon EOS 5D Mark II
[快门] => 1/25
[光圈] => 14/10
[焦距] => 35/1
[感光度] => 2000
[文件格式] => image/jpeg
[时间戳] => -07-24T13:43:47+08:00
[图片说明] =>
[方向1] =>
[方向2] =>
[水平分辨率] => 350/12
[垂直分辨率] => 350/12
[作者] => Photographer: Fisher
[版权] => Copyright:clycsz3
[Exif版本] => 0220
[拍摄分辨率高] => 500
[拍摄分辨率宽] => 750
[拍摄时间] => :07:04 01:12:22
)
图片二
(
[文件名] => pic2.jpg
[文件类型] => 2
[器材品牌] => Exif
[器材] => II*
[快门] => 1111490560/15
[光圈] => 1111490560/15
[焦距] => 1111490560/15
[感光度] => 100
[文件格式] => image/jpeg
[时间戳] =>
[图片说明] =>
[方向1] => 1
[方向2] =>
[水平分辨率] => 16795209/12079598092
[垂直分辨率] => 18432/691327992
[作者] =>
[版权] =>
[Exif版本] => 0230
[拍摄分辨率高] => 915
[拍摄分辨率宽] => 1400
[拍摄时间] =>
)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
(
[文件名] => pic2.jpg
[文件类型] => 2
[器材品牌] => Exif
[器材] => II*
[快门] => 1111490560/15
[光圈] => 1111490560/15
[焦距] => 1111490560/15
[感光度] => 100
[文件格式] => image/jpeg
[时间戳] =>
[图片说明] =>
[方向1] => 1
[方向2] =>
[水平分辨率] => 16795209/12079598092
[垂直分辨率] => 18432/691327992
[作者] =>
[版权] =>
[Exif版本] => 0230
[拍摄分辨率高] => 915
[拍摄分辨率宽] => 1400
[拍摄时间] =>
)
发现第二张图片有些参数取出来的值不对：
[器材品牌] => Exif
[器材] => II*
怀疑是几种原因导致，一是相机设备的exif信息比较新，php的exifi模块无法读取；二是图片被编辑过，部分exif信息被破坏。
下面提供linux下的一个command方式读取exif信息的工具–ImageMagick，ubuntu和centos下都有。
如CentOS下的安装方式： yum install ImageMagick
/usr/bin/identify -verbose pic1.jpg | grep -i exif
exif:ApertureValue: 970854/1000000
exif:Artist: Photographer:Fisher
exif:Copyright: Copyright:clycsz3
exif:DateTime: -07-24T13:43:47+08:00
exif:DateTimeDigitized: :07:04 01:12:22
exif:DateTimeOriginal: :07:04 01:12:22
exif:ExifImageLength: 500
exif:ExifImageWidth: 750
exif:ExifOffset: 276
exif:ExifVersion: 48, 50, 50, 48
exif:ExposureBiasValue: 0/1
exif:ExposureMode: 0
exif:ExposureProgram: 3
exif:ExposureTime: 1/25
exif:Flash: 16
exif:FNumber: 14/10
exif:FocalLength: 35/1
exif:FocalPlaneResolutionUnit: 2
exif:FocalPlaneXResolution: 3861000/1459
exif:FocalPlaneYResolution: 2574000/958
exif:ISOSpeedRatings: 2000
exif:Make: Canon
exif:MaxApertureValue: 1/1
exif:MeteringMode: 5
exif:Model: Canon EOS 5D Mark II
exif:ResolutionUnit: 2
exif:SceneCaptureType: 0
exif:ShutterSpeedValue: 4643856/1000000
exif:Software: Adobe Photoshop CS6 Windows
exif:SubSecTime: 08
exif:SubSecTimeDigitized: 08
exif:SubSecTimeOriginal: 08
exif:WhiteBalance: 0
exif:XResolution: 350/1
exif:YResolution: 350/1
Profile-exif: 708 bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
/usr/bin/identify-verbosepic1.jpg|grep-iexif
exif:ApertureValue:970854/1000000
exif:Artist:Photographer:Fisher
exif:Copyright:Copyright:clycsz3
exif:DateTime:-07-24T13:43:47+08:00
exif:DateTimeDigitized::07:0401:12:22
exif:DateTimeOriginal::07:0401:12:22
exif:ExifImageLength:500
exif:ExifImageWidth:750
exif:ExifOffset:276
exif:ExifVersion:48,50,50,48
exif:ExposureBiasValue:0/1
exif:ExposureMode:0
exif:ExposureProgram:3
exif:ExposureTime:1/25
exif:Flash:16
exif:FNumber:14/10
exif:FocalLength:35/1
exif:FocalPlaneResolutionUnit:2
exif:FocalPlaneXResolution:3861000/1459
exif:FocalPlaneYResolution:2574000/958
exif:ISOSpeedRatings:2000
exif:Make:Canon
exif:MaxApertureValue:1/1
exif:MeteringMode:5
exif:Model:CanonEOS5DMarkII
exif:ResolutionUnit:2
exif:SceneCaptureType:0
exif:ShutterSpeedValue:4643856/1000000
exif:Software:AdobePhotoshopCS6Windows
exif:SubSecTime:08
exif:SubSecTimeDigitized:08
exif:SubSecTimeOriginal:08
exif:WhiteBalance:0
exif:XResolution:350/1
exif:YResolution:350/1
Profile-exif:708bytes
看上去还是比较好用的，看看程序上怎么方便处理和调用吧。
也可以跟/对比一下，看看你取出来的exif信息是否正确。
